patch, 10 partsdiff --color-moved[-ws] speedups

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 52c791574b71..cb068f8258c0 100644
--- a/diff.c
+++ b/diff.c
@@ -1142,6 +1142,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
+	enum diff_symbol last_symbol = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1149,7 +1150,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-		enum diff_symbol last_symbol = 0;
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
@@ -1214,7 +1214,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol != l->s)
+			    pmb_nr && last_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 2c13b62d3c65..920114cd795c 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1442,6 +1442,78 @@ test_expect_success 'detect permutations inside moved code -- dimmed-zebra' '
 	test_cmp expected actual
 '
 
+test_expect_success 'zebra alternate color is only used when necessary' '
+	cat >old.txt <<-\EOF &&
+	line 1A should be marked as oldMoved newMovedAlternate
+	line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	line 2A should be marked as oldMoved newMovedAlternate
+	line 2B should be marked as oldMoved newMovedAlternate
+	line 3A should be marked as oldMovedAlternate newMoved
+	line 3B should be marked as oldMovedAlternate newMoved
+	unchanged
+	line 4A should be marked as oldMoved newMovedAlternate
+	line 4B should be marked as oldMoved newMovedAlternate
+	line 5A should be marked as oldMovedAlternate newMoved
+	line 5B should be marked as oldMovedAlternate newMoved
+	line 6A should be marked as oldMoved newMoved
+	line 6B should be marked as oldMoved newMoved
+	EOF
+	cat >new.txt <<-\EOF &&
+	  line 1A should be marked as oldMoved newMovedAlternate
+	  line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 3A should be marked as oldMovedAlternate newMoved
+	  line 3B should be marked as oldMovedAlternate newMoved
+	  line 2A should be marked as oldMoved newMovedAlternate
+	  line 2B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 6A should be marked as oldMoved newMoved
+	  line 6B should be marked as oldMoved newMoved
+	    line 4A should be marked as oldMoved newMovedAlternate
+	    line 4B should be marked as oldMoved newMovedAlternate
+	  line 5A should be marked as oldMovedAlternate newMoved
+	  line 5B should be marked as oldMovedAlternate newMoved
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		 --color-moved-ws=allow-indentation-change \
+		 old.txt new.txt >output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,14 +1,14 @@<RESET>
+	<BOLD;MAGENTA>-line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;MAGENTA>-line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;MAGENTA>-line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/diff.c b/diff.c
index de6522a3a860..f60cce654c14 100644
--- a/diff.c
+++ b/diff.c
@@ -997,12 +997,12 @@ static void add_lines_to_move_detection(struct diff_options *o,
 static void pmb_advance_or_null(struct diff_options *o,
 				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
-				int pmb_nr)
+				int *pmb_nr)
 {
-	int i;
+	int i, j;
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
-	for (i = 0; i < pmb_nr; i++) {
+	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
@@ -1017,37 +1017,9 @@ static void pmb_advance_or_null(struct diff_options *o,
 				xdiff_compare_lines(cur->es->line, cur->es->len,
 						    l->line, l->len, flags);
 		if (match)
-			pmb[i].match = cur;
-		else
-			moved_block_clear(&pmb[i]);
+			pmb[j++].match = cur;
 	}
-}
-
-static int shrink_potential_moved_blocks(struct moved_block *pmb,
-					 int pmb_nr)
-{
-	int lp, rp;
-
-	/* Shrink the set of potential block to the remaining running */
-	for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
-		while (lp < pmb_nr && pmb[lp].match)
-			lp++;
-		/* lp points at the first NULL now */
-
-		while (rp > -1 && !pmb[rp].match)
-			rp--;
-		/* rp points at the last non-NULL */
-
-		if (lp < pmb_nr && rp > -1 && lp < rp) {
-			pmb[lp] = pmb[rp];
-			memset(&pmb[rp], 0, sizeof(pmb[rp]));
-			rp--;
-			lp++;
-		}
-	}
-
-	/* Remember the number of running sets */
-	return rp + 1;
+	*pmb_nr = j;
 }
 
 /*
@@ -1140,9 +1112,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		pmb_advance_or_null(o, l, pmb, pmb_nr);
-
-		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, &pmb_nr);
 
 		if (pmb_nr == 0) {
 			/*

diff --git a/diff.c b/diff.c
index ee58373f55f8..e6f3586b39bf 100644
--- a/diff.c
+++ b/diff.c
@@ -850,28 +850,15 @@ static void fill_es_indent_data(struct emitted_diff_symbol *es)
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
-			    const struct emitted_diff_symbol *b,
-			    int *out)
-{
-	int a_len = a->len,
-	    b_len = b->len,
-	    a_off = a->indent_off,
-	    a_width = a->indent_width,
-	    b_off = b->indent_off,
+			    const struct emitted_diff_symbol *b)
+{
+	int a_width = a->indent_width,
 	    b_width = b->indent_width;
 
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
-		*out = INDENT_BLANKLINE;
-		return 1;
-	}
-
-	if (a_len - a_off != b_len - b_off ||
-	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
-		return 0;
-
-	*out = a_width - b_width;
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+		return INDENT_BLANKLINE;
 
-	return 1;
+	return a_width - b_width;
 }
 
 static int cmp_in_block_with_wsd(const struct diff_options *o,
@@ -917,26 +904,17 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 			   const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
-	const struct moved_entry *a, *b;
+	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent);
-	b = container_of(entry_or_key, const struct moved_entry, ent);
-
-	if (diffopt->color_moved_ws_handling &
-	    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-		/*
-		 * As there is not specific white space config given,
-		 * we'd need to check for a new block, so ignore all
-		 * white space. The setup of the white space
-		 * configuration for the next block is done else where
-		 */
-		flags |= XDF_IGNORE_WHITESPACE;
+	a = container_of(eptr, const struct moved_entry, ent)->es;
+	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
 
-	return !xdiff_compare_lines(a->es->line, a->es->len,
-				    b->es->line, b->es->len,
-				    flags);
+	return !xdiff_compare_lines(a->line + a->indent_off,
+				    a->len - a->indent_off,
+				    b->line + b->indent_off,
+				    b->len - b->indent_off, flags);
 }
 
 static struct moved_entry *prepare_entry(struct diff_options *o,
@@ -945,7 +923,8 @@ static struct moved_entry *prepare_entry(struct diff_options *o,
 	struct moved_entry *ret = xmalloc(sizeof(*ret));
 	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
-	unsigned int hash = xdiff_hash_string(l->line, l->len, flags);
+	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
+					      l->len - l->indent_off, flags);
 
 	hashmap_entry_init(&ret->ent, hash);
 	ret->es = l;
@@ -1113,14 +1092,11 @@ static void mark_color_as_moved(struct diff_options *o,
 			hashmap_for_each_entry_from(hm, match, ent) {
 				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 				if (o->color_moved_ws_handling &
-				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-					if (compute_ws_delta(l, match->es,
-							     &pmb[pmb_nr].wsd))
-						pmb[pmb_nr++].match = match;
-				} else {
+				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+					pmb[pmb_nr].wsd = compute_ws_delta(l, match->es);
+				else
 					pmb[pmb_nr].wsd = 0;
-					pmb[pmb_nr++].match = match;
-				}
+				pmb[pmb_nr++].match = match;
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
@@ -6240,10 +6216,6 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 		if (o->color_moved) {
 			struct hashmap add_lines, del_lines;
 
-			if (o->color_moved_ws_handling &
-			    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-				o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
-
 			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
 			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
 

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index cb068f8258c0..a0c43a104768 100644
--- a/diff.c
+++ b/diff.c
@@ -1142,7 +1142,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
-	enum diff_symbol last_symbol = 0;
+	enum diff_symbol moved_symbol = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1168,7 +1168,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			flipped_block = 0;
 		}
 
-		if (!match) {
+		if (pmb_nr && (!match || l->s != moved_symbol)) {
 			int i;
 
 			adjust_last_block(o, n, block_length);
@@ -1177,12 +1177,13 @@ static void mark_color_as_moved(struct diff_options *o,
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
-			last_symbol = l->s;
+		}
+		if (!match) {
+			moved_symbol = 0;
 			continue;
 		}
 
 		if (o->color_moved == COLOR_MOVED_PLAIN) {
-			last_symbol = l->s;
 			l->flags |= DIFF_SYMBOL_MOVED_LINE;
 			continue;
 		}
@@ -1214,11 +1215,16 @@ static void mark_color_as_moved(struct diff_options *o,
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol == l->s)
+			    pmb_nr && moved_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
 
+			if (pmb_nr)
+				moved_symbol = l->s;
+			else
+				moved_symbol = 0;
+
 			block_length = 0;
 		}
 
@@ -1228,7 +1234,6 @@ static void mark_color_as_moved(struct diff_options *o,
 			if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 				l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 		}
-		last_symbol = l->s;
 	}
 	adjust_last_block(o, n, block_length);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 920114cd795c..3119a59f071d 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1514,6 +1514,71 @@ test_expect_success 'zebra alternate color is only used when necessary' '
 	test_cmp expected actual
 '
 
+test_expect_success 'short lines of opposite sign do not get marked as moved' '
+	cat >old.txt <<-\EOF &&
+	this line should be marked as moved
+	unchanged
+	unchanged
+	unchanged
+	unchanged
+	too short
+	this line should be marked as oldMoved newMoved
+	this line should be marked as oldMovedAlternate newMoved
+	unchanged 1
+	unchanged 2
+	unchanged 3
+	unchanged 4
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	EOF
+	cat >new.txt <<-\EOF &&
+	too short
+	unchanged
+	unchanged
+	this line should be marked as moved
+	too short
+	unchanged
+	unchanged
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 1
+	unchanged 2
+	this line should be marked as oldMovedAlternate newMoved
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 3
+	this line should be marked as oldMoved newMoved
+	unchanged 4
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		old.txt new.txt >output && cat output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expect <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,13 +1,15 @@<RESET>
+	<BOLD;MAGENTA>-this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<RED>-too short<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved<RESET>
+	<BOLD;BLUE>-this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 1<RESET>
+	 unchanged 2<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 3<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved<RESET>
+	 unchanged 4<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/diff.c b/diff.c
index a0c43a104768..19c8954ec546 100644
--- a/diff.c
+++ b/diff.c
@@ -864,23 +864,17 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	    a_width = a->indent_width,
 	    b_off = b->indent_off,
 	    b_width = b->indent_width;
-	int delta;
 
 	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 		*out = INDENT_BLANKLINE;
 		return 1;
 	}
 
-	if (a->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - b_width;
-	else
-		delta = b_width - a_width;
-
 	if (a_len - a_off != b_len - b_off ||
 	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 		return 0;
 
-	*out = delta;
+	*out = a_width - b_width;
 
 	return 1;
 }
@@ -924,10 +918,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	if (cur->es->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - c_width;
-	else
-		delta = c_width - a_width;
+	delta = c_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its

diff --git a/diff.c b/diff.c
index 19c8954ec546..5d5d168107a6 100644
--- a/diff.c
+++ b/diff.c
@@ -881,35 +881,20 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 
 static int cmp_in_block_with_wsd(const struct diff_options *o,
 				 const struct moved_entry *cur,
-				 const struct moved_entry *match,
-				 struct moved_block *pmb,
-				 int n)
+				 const struct emitted_diff_symbol *l,
+				 struct moved_block *pmb)
 {
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-	int al = cur->es->len, bl = match->es->len, cl = l->len;
+	int al = cur->es->len, bl = l->len;
 	const char *a = cur->es->line,
-		   *b = match->es->line,
-		   *c = l->line;
+		   *b = l->line;
 	int a_off = cur->es->indent_off,
 	    a_width = cur->es->indent_width,
-	    c_off = l->indent_off,
-	    c_width = l->indent_width;
+	    b_off = l->indent_off,
+	    b_width = l->indent_width;
 	int delta;
 
-	/*
-	 * We need to check if 'cur' is equal to 'match'.  As those
-	 * are from the same (+/-) side, we do not need to adjust for
-	 * indent changes. However these were found using fuzzy
-	 * matching so we do have to check if they are equal. Here we
-	 * just check the lengths. We delay calling memcmp() to check
-	 * the contents until later as if the length comparison for a
-	 * and c fails we can avoid the call all together.
-	 */
-	if (al != bl)
-		return 1;
-
 	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
@@ -918,7 +903,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	delta = c_width - a_width;
+	delta = b_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its
@@ -927,9 +912,8 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == cl - c_off &&
-		 !memcmp(a, b, al) && !
-		 memcmp(a + a_off, c + c_off, al - a_off));
+	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
+		 !memcmp(a + a_off, b + b_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -1030,36 +1014,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct moved_entry *match,
-					    struct hashmap *hm,
+					    struct emitted_diff_symbol *l,
 					    struct moved_block *pmb,
-					    int pmb_nr, int n)
+					    int pmb_nr)
 {
 	int i;
-	char *got_match = xcalloc(1, pmb_nr);
-
-	hashmap_for_each_entry_from(hm, match, ent) {
-		for (i = 0; i < pmb_nr; i++) {
-			struct moved_entry *prev = pmb[i].match;
-			struct moved_entry *cur = (prev && prev->next_line) ?
-					prev->next_line : NULL;
-			if (!cur)
-				continue;
-			if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
-				got_match[i] |= 1;
-		}
-	}
 
 	for (i = 0; i < pmb_nr; i++) {
-		if (got_match[i]) {
+		struct moved_entry *prev = pmb[i].match;
+		struct moved_entry *cur = (prev && prev->next_line) ?
+			prev->next_line : NULL;
+		if (cur && !cmp_in_block_with_wsd(o, cur, l, &pmb[i])) {
 			/* Advance to the next line */
-			pmb[i].match = pmb[i].match->next_line;
+			pmb[i].match = cur;
 		} else {
 			moved_block_clear(&pmb[i]);
 		}
 	}
-
-	free(got_match);
 }
 
 static int shrink_potential_moved_blocks(struct moved_block *pmb,
@@ -1181,7 +1152,7 @@ static void mark_color_as_moved(struct diff_options *o,
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
+			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
 			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 5d5d168107a6..c8fdfc9049bb 100644
--- a/diff.c
+++ b/diff.c
@@ -995,17 +995,20 @@ static void add_lines_to_move_detection(struct diff_options *o,
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
-				struct moved_entry *match,
-				struct hashmap *hm,
+				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
 				int pmb_nr)
 {
 	int i;
+	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
+
 	for (i = 0; i < pmb_nr; i++) {
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && !hm->cmpfn(o, &cur->ent, &match->ent, NULL)) {
+		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
+						l->line, l->len,
+						flags)) {
 			pmb[i].match = cur;
 		} else {
 			pmb[i].match = NULL;
@@ -1154,7 +1157,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
-			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
+			pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index c8fdfc9049bb..de6522a3a860 100644
--- a/diff.c
+++ b/diff.c
@@ -1003,36 +1003,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0; i < pmb_nr; i++) {
+		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
-						l->line, l->len,
-						flags)) {
-			pmb[i].match = cur;
-		} else {
-			pmb[i].match = NULL;
-		}
-	}
-}
 
-static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct emitted_diff_symbol *l,
-					    struct moved_block *pmb,
-					    int pmb_nr)
-{
-	int i;
-
-	for (i = 0; i < pmb_nr; i++) {
-		struct moved_entry *prev = pmb[i].match;
-		struct moved_entry *cur = (prev && prev->next_line) ?
-			prev->next_line : NULL;
-		if (cur && !cmp_in_block_with_wsd(o, cur, l, &pmb[i])) {
-			/* Advance to the next line */
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			match = cur &&
+				!cmp_in_block_with_wsd(o, cur, l, &pmb[i]);
+		else
+			match = cur &&
+				xdiff_compare_lines(cur->es->line, cur->es->len,
+						    l->line, l->len, flags);
+		if (match)
 			pmb[i].match = cur;
-		} else {
+		else
 			moved_block_clear(&pmb[i]);
-		}
 	}
 }
 
@@ -1153,11 +1140,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
-		else
-			pmb_advance_or_null(o, l, pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index e6f3586b39bf..3260e2c60591 100644
--- a/diff.c
+++ b/diff.c
@@ -18,6 +18,7 @@
 #include "submodule-config.h"
 #include "submodule.h"
 #include "hashmap.h"
+#include "mem-pool.h"
 #include "ll-merge.h"
 #include "string-list.h"
 #include "strvec.h"
@@ -772,6 +773,7 @@ struct emitted_diff_symbol {
 	int flags;
 	int indent_off;   /* Offset to first non-whitespace character */
 	int indent_width; /* The visual width of the indentation */
+	unsigned id;
 	enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -797,9 +799,9 @@ static void append_emitted_diff_symbol(struct diff_options *o,
 }
 
 struct moved_entry {
-	struct hashmap_entry ent;
 	const struct emitted_diff_symbol *es;
 	struct moved_entry *next_line;
+	struct moved_entry *next_match;
 };
 
 struct moved_block {
@@ -866,24 +868,24 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 				 const struct emitted_diff_symbol *l,
 				 struct moved_block *pmb)
 {
-	int al = cur->es->len, bl = l->len;
-	const char *a = cur->es->line,
-		   *b = l->line;
-	int a_off = cur->es->indent_off,
-	    a_width = cur->es->indent_width,
-	    b_off = l->indent_off,
-	    b_width = l->indent_width;
+	int a_width = cur->es->indent_width, b_width = l->indent_width;
 	int delta;
 
-	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+	/* The text of each line must match */
+	if (cur->es->id != l->id)
+		return 1;
+
+	/*
+	 * If 'l' and 'cur' are both blank then we don't need to check the
+	 * indent. We only need to check cur as we know the strings match.
+	 * */
+	if (a_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
 	 * The indent changes of the block are known and stored in pmb->wsd;
 	 * however we need to check if the indent changes of the current line
-	 * match those of the current block and that the text of 'l' and 'cur'
-	 * after the indentation match.
+	 * match those of the current block.
 	 */
 	delta = b_width - a_width;
 
@@ -894,22 +896,26 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
-		 !memcmp(a + a_off, b + b_off, al - a_off));
+	return delta != pmb->wsd;
 }
 
-static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
-			   const struct hashmap_entry *eptr,
-			   const struct hashmap_entry *entry_or_key,
-			   const void *keydata)
+struct interned_diff_symbol {
+	struct hashmap_entry ent;
+	struct emitted_diff_symbol *es;
+};
+
+static int interned_diff_symbol_cmp(const void *hashmap_cmp_fn_data,
+				    const struct hashmap_entry *eptr,
+				    const struct hashmap_entry *entry_or_key,
+				    const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
 	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent)->es;
-	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
+	a = container_of(eptr, const struct interned_diff_symbol, ent)->es;
+	b = container_of(entry_or_key, const struct interned_diff_symbol, ent)->es;
 
 	return !xdiff_compare_lines(a->line + a->indent_off,
 				    a->len - a->indent_off,
@@ -917,55 +923,81 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 				    b->len - b->indent_off, flags);
 }
 
-static struct moved_entry *prepare_entry(struct diff_options *o,
-					 int line_no)
+static void prepare_entry(struct diff_options *o, struct emitted_diff_symbol *l,
+			  struct interned_diff_symbol *s)
 {
-	struct moved_entry *ret = xmalloc(sizeof(*ret));
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
 					      l->len - l->indent_off, flags);
 
-	hashmap_entry_init(&ret->ent, hash);
-	ret->es = l;
-	ret->next_line = NULL;
-
-	return ret;
+	hashmap_entry_init(&s->ent, hash);
+	s->es = l;
 }
 
-static void add_lines_to_move_detection(struct diff_options *o,
-					struct hashmap *add_lines,
-					struct hashmap *del_lines)
+struct moved_entry_list {
+	struct moved_entry *add, *del;
+};
+
+static struct moved_entry_list *add_lines_to_move_detection(struct diff_options *o,
+							    struct mem_pool *entry_mem_pool)
 {
 	struct moved_entry *prev_line = NULL;
-
+	struct mem_pool interned_pool;
+	struct hashmap interned_map;
+	struct moved_entry_list *entry_list = NULL;
+	size_t entry_list_alloc = 0;
+	unsigned id = 0;
 	int n;
+
+	hashmap_init(&interned_map, interned_diff_symbol_cmp, o, 8096);
+	mem_pool_init(&interned_pool, 1024 * 1024);
+
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm;
-		struct moved_entry *key;
+		struct interned_diff_symbol key;
+		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+		struct interned_diff_symbol *s;
+		struct moved_entry *entry;
 
-		switch (o->emitted_symbols->buf[n].s) {
-		case DIFF_SYMBOL_PLUS:
-			hm = add_lines;
-			break;
-		case DIFF_SYMBOL_MINUS:
-			hm = del_lines;
-			break;
-		default:
+		if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS) {
 			prev_line = NULL;
 			continue;
 		}
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			fill_es_indent_data(&o->emitted_symbols->buf[n]);
-		key = prepare_entry(o, n);
-		if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
-			prev_line->next_line = key;
+			fill_es_indent_data(l);
 
-		hashmap_add(hm, &key->ent);
-		prev_line = key;
+		prepare_entry(o, l, &key);
+		s = hashmap_get_entry(&interned_map, &key, ent, &key.ent);
+		if (s) {
+			l->id = s->es->id;
+		} else {
+			l->id = id;
+			ALLOC_GROW_BY(entry_list, id, 1, entry_list_alloc);
+			hashmap_add(&interned_map,
+				    memcpy(mem_pool_alloc(&interned_pool,
+							  sizeof(key)),
+					   &key, sizeof(key)));
+		}
+		entry = mem_pool_alloc(entry_mem_pool, sizeof(*entry));
+		entry->es = l;
+		entry->next_line = NULL;
+		if (prev_line && prev_line->es->s == l->s)
+			prev_line->next_line = entry;
+		prev_line = entry;
+		if (l->s == DIFF_SYMBOL_PLUS) {
+			entry->next_match = entry_list[l->id].add;
+			entry_list[l->id].add = entry;
+		} else {
+			entry->next_match = entry_list[l->id].del;
+			entry_list[l->id].del = entry;
+		}
 	}
+
+	hashmap_clear(&interned_map);
+	mem_pool_discard(&interned_pool, 0);
+
+	return entry_list;
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
@@ -974,7 +1006,6 @@ static void pmb_advance_or_null(struct diff_options *o,
 				int *pmb_nr)
 {
 	int i, j;
-	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
@@ -987,9 +1018,8 @@ static void pmb_advance_or_null(struct diff_options *o,
 			match = cur &&
 				!cmp_in_block_with_wsd(o, cur, l, &pmb[i]);
 		else
-			match = cur &&
-				xdiff_compare_lines(cur->es->line, cur->es->len,
-						    l->line, l->len, flags);
+			match = cur && cur->es->id == l->id;
+
 		if (match)
 			pmb[j++].match = cur;
 	}
@@ -1034,8 +1064,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
 static void mark_color_as_moved(struct diff_options *o,
-				struct hashmap *add_lines,
-				struct hashmap *del_lines)
+				struct moved_entry_list *entry_list)
 {
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
@@ -1044,23 +1073,15 @@ static void mark_color_as_moved(struct diff_options *o,
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm = NULL;
-		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
-			hm = del_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].del;
 			break;
 		case DIFF_SYMBOL_MINUS:
-			hm = add_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].add;
 			break;
 		default:
 			flipped_block = 0;
@@ -1089,7 +1110,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			 * The current line is the start of a new block.
 			 * Setup the set of potential blocks.
 			 */
-			hashmap_for_each_entry_from(hm, match, ent) {
+			for (; match; match = match->next_match) {
 				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 				if (o->color_moved_ws_handling &
 				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -1460,7 +1481,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len, unsigned flags)
 {
-	struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
+	struct emitted_diff_symbol e = {line, len, flags, 0, 0, 0, s};
 
 	if (o->emitted_symbols)
 		append_emitted_diff_symbol(o, &e);
@@ -6214,20 +6235,18 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 
 	if (o->emitted_symbols) {
 		if (o->color_moved) {
-			struct hashmap add_lines, del_lines;
-
-			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
-			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
+			struct mem_pool entry_pool;
+			struct moved_entry_list *entry_list;
 
-			add_lines_to_move_detection(o, &add_lines, &del_lines);
-			mark_color_as_moved(o, &add_lines, &del_lines);
+			mem_pool_init(&entry_pool, 1024 * 1024);
+			entry_list = add_lines_to_move_detection(o,
+								 &entry_pool);
+			mark_color_as_moved(o, entry_list);
 			if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
 				dim_moved_lines(o);
 
-			hashmap_clear_and_free(&add_lines, struct moved_entry,
-						ent);
-			hashmap_clear_and_free(&del_lines, struct moved_entry,
-						ent);
+			mem_pool_discard(&entry_pool, 0);
+			free(entry_list);
 		}
 
 		for (i = 0; i < esm.nr; i++)

diff --git a/diff.c b/diff.c
index f60cce654c14..ee58373f55f8 100644
--- a/diff.c
+++ b/diff.c
@@ -807,11 +807,6 @@ struct moved_block {
 	int wsd; /* The whitespace delta of this block */
 };
 
-static void moved_block_clear(struct moved_block *b)
-{
-	memset(b, 0, sizeof(*b));
-}
-
 #define INDENT_BLANKLINE INT_MIN
 
 static void fill_es_indent_data(struct emitted_diff_symbol *es)
@@ -1093,11 +1088,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		}
 
 		if (pmb_nr && (!match || l->s != moved_symbol)) {
-			int i;
-
 			adjust_last_block(o, n, block_length);
-			for(i = 0; i < pmb_nr; i++)
-				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
@@ -1155,8 +1146,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	}
 	adjust_last_block(o, n, block_length);
 
-	for(n = 0; n < pmb_nr; n++)
-		moved_block_clear(&pmb[n]);
 	free(pmb);
 }
 

diff --git a/diff.c b/diff.c
index 77c893b266a..55384449170 100644
--- a/diff.c
+++ b/diff.c
@@ -881,35 +881,20 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 
 static int cmp_in_block_with_wsd(const struct diff_options *o,
 				 const struct moved_entry *cur,
-				 const struct moved_entry *match,
-				 struct moved_block *pmb,
-				 int n)
+				 const struct emitted_diff_symbol *l,
+				 struct moved_block *pmb)
 {
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-	int al = cur->es->len, bl = match->es->len, cl = l->len;
+	int al = cur->es->len, bl = l->len;
 	const char *a = cur->es->line,
-		   *b = match->es->line,
-		   *c = l->line;
+		   *b = l->line;
 	int a_off = cur->es->indent_off,
 	    a_width = cur->es->indent_width,
-	    c_off = l->indent_off,
-	    c_width = l->indent_width;
+	    b_off = l->indent_off,
+	    b_width = l->indent_width;
 	int delta;
 
-	/*
-	 * We need to check if 'cur' is equal to 'match'.  As those
-	 * are from the same (+/-) side, we do not need to adjust for
-	 * indent changes. However these were found using fuzzy
-	 * matching so we do have to check if they are equal. Here we
-	 * just check the lengths. We delay calling memcmp() to check
-	 * the contents until later as if the length comparison for a
-	 * and c fails we can avoid the call all together.
-	 */
-	if (al != bl)
-		return 1;
-
 	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
@@ -918,7 +903,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	delta = c_width - a_width;
+	delta = b_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its
@@ -927,9 +912,8 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == cl - c_off &&
-		 !memcmp(a, b, al) && !
-		 memcmp(a + a_off, c + c_off, al - a_off));
+	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
+		 !memcmp(a + a_off, b + b_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -1030,36 +1014,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct moved_entry *match,
-					    struct hashmap *hm,
+					    struct emitted_diff_symbol *l,
 					    struct moved_block *pmb,
-					    int pmb_nr, int n)
+					    int pmb_nr)
 {
 	int i;
-	char *got_match = xcalloc(1, pmb_nr);
-
-	hashmap_for_each_entry_from(hm, match, ent) {
-		for (i = 0; i < pmb_nr; i++) {
-			struct moved_entry *prev = pmb[i].match;
-			struct moved_entry *cur = (prev && prev->next_line) ?
-					prev->next_line : NULL;
-			if (!cur)
-				continue;
-			if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
-				got_match[i] |= 1;
-		}
-	}
 
 	for (i = 0; i < pmb_nr; i++) {
-		if (got_match[i]) {
+		struct moved_entry *prev = pmb[i].match;
+		struct moved_entry *cur = (prev && prev->next_line) ?
+			prev->next_line : NULL;
+		if (cur && !cmp_in_block_with_wsd(o, cur, l, &pmb[i])) {
 			/* Advance to the next line */
-			pmb[i].match = pmb[i].match->next_line;
+			pmb[i].match = cur;
 		} else {
 			moved_block_clear(&pmb[i]);
 		}
 	}
-
-	free(got_match);
 }
 
 static int shrink_potential_moved_blocks(struct moved_block *pmb,
@@ -1181,7 +1152,7 @@ static void mark_color_as_moved(struct diff_options *o,
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
+			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
 			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 2b51b77fd20..77c893b266a 100644
--- a/diff.c
+++ b/diff.c
@@ -864,23 +864,17 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	    a_width = a->indent_width,
 	    b_off = b->indent_off,
 	    b_width = b->indent_width;
-	int delta;
 
 	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 		*out = INDENT_BLANKLINE;
 		return 1;
 	}
 
-	if (a->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - b_width;
-	else
-		delta = b_width - a_width;
-
 	if (a_len - a_off != b_len - b_off ||
 	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 		return 0;
 
-	*out = delta;
+	*out = a_width - b_width;
 
 	return 1;
 }
@@ -924,10 +918,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	if (cur->es->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - c_width;
-	else
-		delta = c_width - a_width;
+	delta = c_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index cb068f8258c..2b51b77fd20 100644
--- a/diff.c
+++ b/diff.c
@@ -1142,7 +1142,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
-	enum diff_symbol last_symbol = 0;
+	enum diff_symbol moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1168,7 +1168,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			flipped_block = 0;
 		}
 
-		if (!match) {
+		if (pmb_nr && (!match || l->s != moved_symbol)) {
 			int i;
 
 			adjust_last_block(o, n, block_length);
@@ -1177,12 +1177,13 @@ static void mark_color_as_moved(struct diff_options *o,
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
-			last_symbol = l->s;
+		}
+		if (!match) {
+			moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 			continue;
 		}
 
 		if (o->color_moved == COLOR_MOVED_PLAIN) {
-			last_symbol = l->s;
 			l->flags |= DIFF_SYMBOL_MOVED_LINE;
 			continue;
 		}
@@ -1214,11 +1215,16 @@ static void mark_color_as_moved(struct diff_options *o,
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol == l->s)
+			    pmb_nr && moved_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
 
+			if (pmb_nr)
+				moved_symbol = l->s;
+			else
+				moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
+
 			block_length = 0;
 		}
 
@@ -1228,7 +1234,6 @@ static void mark_color_as_moved(struct diff_options *o,
 			if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 				l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 		}
-		last_symbol = l->s;
 	}
 	adjust_last_block(o, n, block_length);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 920114cd795..3119a59f071 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1514,6 +1514,71 @@ test_expect_success 'zebra alternate color is only used when necessary' '
 	test_cmp expected actual
 '
 
+test_expect_success 'short lines of opposite sign do not get marked as moved' '
+	cat >old.txt <<-\EOF &&
+	this line should be marked as moved
+	unchanged
+	unchanged
+	unchanged
+	unchanged
+	too short
+	this line should be marked as oldMoved newMoved
+	this line should be marked as oldMovedAlternate newMoved
+	unchanged 1
+	unchanged 2
+	unchanged 3
+	unchanged 4
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	EOF
+	cat >new.txt <<-\EOF &&
+	too short
+	unchanged
+	unchanged
+	this line should be marked as moved
+	too short
+	unchanged
+	unchanged
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 1
+	unchanged 2
+	this line should be marked as oldMovedAlternate newMoved
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 3
+	this line should be marked as oldMoved newMoved
+	unchanged 4
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		old.txt new.txt >output && cat output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expect <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,13 +1,15 @@<RESET>
+	<BOLD;MAGENTA>-this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<RED>-too short<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved<RESET>
+	<BOLD;BLUE>-this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 1<RESET>
+	 unchanged 2<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 3<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved<RESET>
+	 unchanged 4<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 52c791574b7..cb068f8258c 100644
--- a/diff.c
+++ b/diff.c
@@ -1142,6 +1142,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
+	enum diff_symbol last_symbol = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1149,7 +1150,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-		enum diff_symbol last_symbol = 0;
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
@@ -1214,7 +1214,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol != l->s)
+			    pmb_nr && last_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 2c13b62d3c6..920114cd795 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1442,6 +1442,78 @@ test_expect_success 'detect permutations inside moved code -- dimmed-zebra' '
 	test_cmp expected actual
 '
 
+test_expect_success 'zebra alternate color is only used when necessary' '
+	cat >old.txt <<-\EOF &&
+	line 1A should be marked as oldMoved newMovedAlternate
+	line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	line 2A should be marked as oldMoved newMovedAlternate
+	line 2B should be marked as oldMoved newMovedAlternate
+	line 3A should be marked as oldMovedAlternate newMoved
+	line 3B should be marked as oldMovedAlternate newMoved
+	unchanged
+	line 4A should be marked as oldMoved newMovedAlternate
+	line 4B should be marked as oldMoved newMovedAlternate
+	line 5A should be marked as oldMovedAlternate newMoved
+	line 5B should be marked as oldMovedAlternate newMoved
+	line 6A should be marked as oldMoved newMoved
+	line 6B should be marked as oldMoved newMoved
+	EOF
+	cat >new.txt <<-\EOF &&
+	  line 1A should be marked as oldMoved newMovedAlternate
+	  line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 3A should be marked as oldMovedAlternate newMoved
+	  line 3B should be marked as oldMovedAlternate newMoved
+	  line 2A should be marked as oldMoved newMovedAlternate
+	  line 2B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 6A should be marked as oldMoved newMoved
+	  line 6B should be marked as oldMoved newMoved
+	    line 4A should be marked as oldMoved newMovedAlternate
+	    line 4B should be marked as oldMoved newMovedAlternate
+	  line 5A should be marked as oldMovedAlternate newMoved
+	  line 5B should be marked as oldMovedAlternate newMoved
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		 --color-moved-ws=allow-indentation-change \
+		 old.txt new.txt >output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,14 +1,14 @@<RESET>
+	<BOLD;MAGENTA>-line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;MAGENTA>-line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;MAGENTA>-line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/t/perf/p4002-diff-color-moved.sh b/t/perf/p4002-diff-color-moved.sh
new file mode 100755
index 00000000000..ad56bcb71e4
--- /dev/null
+++ b/t/perf/p4002-diff-color-moved.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+
+test_description='Tests diff --color-moved performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+if ! git rev-parse --verify v2.29.0^{commit} >/dev/null
+then
+	skip_all='skipping because tag v2.29.0 was not found'
+	test_done
+fi
+
+GIT_PAGER_IN_USE=1
+test_export GIT_PAGER_IN_USE
+
+test_perf 'diff --no-color-moved --no-color-moved-ws large change' '
+	git diff --no-color-moved --no-color-moved-ws v2.28.0 v2.29.0
+'
+
+test_perf 'diff --color-moved --no-color-moved-ws large change' '
+	git diff --color-moved=zebra --no-color-moved-ws v2.28.0 v2.29.0
+'
+
+test_perf 'diff --color-moved-ws=allow-indentation-change large change' '
+	git diff --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		v2.28.0 v2.29.0
+'
+
+test_perf 'log --no-color-moved --no-color-moved-ws' '
+	git log --no-color-moved --no-color-moved-ws --no-merges --patch \
+		-n1000 v2.29.0
+'
+
+test_perf 'log --color-moved --no-color-moved-ws' '
+	git log --color-moved=zebra --no-color-moved-ws --no-merges --patch \
+		-n1000 v2.29.0
+'
+
+test_perf 'log --color-moved-ws=allow-indentation-change' '
+	git log --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		--no-merges --patch -n1000 v2.29.0
+'
+
+test_done

diff --git a/diff.c b/diff.c
index c056d917d0d..b03f79b626c 100644
--- a/diff.c
+++ b/diff.c
@@ -1003,36 +1003,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0; i < pmb_nr; i++) {
+		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
-						l->line, l->len,
-						flags)) {
-			pmb[i].match = cur;
-		} else {
-			pmb[i].match = NULL;
-		}
-	}
-}
 
-static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct emitted_diff_symbol *l,
-					    struct moved_block *pmb,
-					    int pmb_nr)
-{
-	int i;
-
-	for (i = 0; i < pmb_nr; i++) {
-		struct moved_entry *prev = pmb[i].match;
-		struct moved_entry *cur = (prev && prev->next_line) ?
-			prev->next_line : NULL;
-		if (cur && !cmp_in_block_with_wsd(o, cur, l, &pmb[i])) {
-			/* Advance to the next line */
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			match = cur &&
+				!cmp_in_block_with_wsd(o, cur, l, &pmb[i]);
+		else
+			match = cur &&
+				xdiff_compare_lines(cur->es->line, cur->es->len,
+						    l->line, l->len, flags);
+		if (match)
 			pmb[i].match = cur;
-		} else {
+		else
 			moved_block_clear(&pmb[i]);
-		}
 	}
 }
 
@@ -1153,11 +1140,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
-		else
-			pmb_advance_or_null(o, l, pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 55384449170..c056d917d0d 100644
--- a/diff.c
+++ b/diff.c
@@ -995,17 +995,20 @@ static void add_lines_to_move_detection(struct diff_options *o,
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
-				struct moved_entry *match,
-				struct hashmap *hm,
+				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
 				int pmb_nr)
 {
 	int i;
+	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
+
 	for (i = 0; i < pmb_nr; i++) {
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && !hm->cmpfn(o, &cur->ent, &match->ent, NULL)) {
+		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
+						l->line, l->len,
+						flags)) {
 			pmb[i].match = cur;
 		} else {
 			pmb[i].match = NULL;
@@ -1154,7 +1157,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
-			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
+			pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 068473c0be3..4b5776a5a0a 100644
--- a/diff.c
+++ b/diff.c
@@ -807,11 +807,6 @@ struct moved_block {
 	int wsd; /* The whitespace delta of this block */
 };
 
-static void moved_block_clear(struct moved_block *b)
-{
-	memset(b, 0, sizeof(*b));
-}
-
 #define INDENT_BLANKLINE INT_MIN
 
 static void fill_es_indent_data(struct emitted_diff_symbol *es)
@@ -1093,11 +1088,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		}
 
 		if (pmb_nr && (!match || l->s != moved_symbol)) {
-			int i;
-
 			adjust_last_block(o, n, block_length);
-			for(i = 0; i < pmb_nr; i++)
-				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
@@ -1155,8 +1146,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	}
 	adjust_last_block(o, n, block_length);
 
-	for(n = 0; n < pmb_nr; n++)
-		moved_block_clear(&pmb[n]);
 	free(pmb);
 }
 

diff --git a/diff.c b/diff.c
index b03f79b626c..068473c0be3 100644
--- a/diff.c
+++ b/diff.c
@@ -997,12 +997,12 @@ static void add_lines_to_move_detection(struct diff_options *o,
 static void pmb_advance_or_null(struct diff_options *o,
 				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
-				int pmb_nr)
+				int *pmb_nr)
 {
-	int i;
+	int i, j;
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
-	for (i = 0; i < pmb_nr; i++) {
+	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
@@ -1017,37 +1017,9 @@ static void pmb_advance_or_null(struct diff_options *o,
 				xdiff_compare_lines(cur->es->line, cur->es->len,
 						    l->line, l->len, flags);
 		if (match)
-			pmb[i].match = cur;
-		else
-			moved_block_clear(&pmb[i]);
+			pmb[j++].match = cur;
 	}
-}
-
-static int shrink_potential_moved_blocks(struct moved_block *pmb,
-					 int pmb_nr)
-{
-	int lp, rp;
-
-	/* Shrink the set of potential block to the remaining running */
-	for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
-		while (lp < pmb_nr && pmb[lp].match)
-			lp++;
-		/* lp points at the first NULL now */
-
-		while (rp > -1 && !pmb[rp].match)
-			rp--;
-		/* rp points at the last non-NULL */
-
-		if (lp < pmb_nr && rp > -1 && lp < rp) {
-			pmb[lp] = pmb[rp];
-			memset(&pmb[rp], 0, sizeof(pmb[rp]));
-			rp--;
-			lp++;
-		}
-	}
-
-	/* Remember the number of running sets */
-	return rp + 1;
+	*pmb_nr = j;
 }
 
 /*
@@ -1140,9 +1112,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		pmb_advance_or_null(o, l, pmb, pmb_nr);
-
-		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, &pmb_nr);
 
 		if (pmb_nr == 0) {
 			/*

diff --git a/diff.c b/diff.c
index f899083d028..31a20a34240 100644
--- a/diff.c
+++ b/diff.c
@@ -1460,7 +1460,9 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len, unsigned flags)
 {
-	struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
+	struct emitted_diff_symbol e = {
+		.line = line, .len = len, .flags = flags, .s = s
+	};
 
 	if (o->emitted_symbols)
 		append_emitted_diff_symbol(o, &e);

diff --git a/diff.c b/diff.c
index 4b5776a5a0a..f899083d028 100644
--- a/diff.c
+++ b/diff.c
@@ -850,28 +850,15 @@ static void fill_es_indent_data(struct emitted_diff_symbol *es)
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
-			    const struct emitted_diff_symbol *b,
-			    int *out)
-{
-	int a_len = a->len,
-	    b_len = b->len,
-	    a_off = a->indent_off,
-	    a_width = a->indent_width,
-	    b_off = b->indent_off,
+			    const struct emitted_diff_symbol *b)
+{
+	int a_width = a->indent_width,
 	    b_width = b->indent_width;
 
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
-		*out = INDENT_BLANKLINE;
-		return 1;
-	}
-
-	if (a_len - a_off != b_len - b_off ||
-	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
-		return 0;
-
-	*out = a_width - b_width;
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+		return INDENT_BLANKLINE;
 
-	return 1;
+	return a_width - b_width;
 }
 
 static int cmp_in_block_with_wsd(const struct diff_options *o,
@@ -917,26 +904,17 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 			   const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
-	const struct moved_entry *a, *b;
+	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent);
-	b = container_of(entry_or_key, const struct moved_entry, ent);
-
-	if (diffopt->color_moved_ws_handling &
-	    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-		/*
-		 * As there is not specific white space config given,
-		 * we'd need to check for a new block, so ignore all
-		 * white space. The setup of the white space
-		 * configuration for the next block is done else where
-		 */
-		flags |= XDF_IGNORE_WHITESPACE;
+	a = container_of(eptr, const struct moved_entry, ent)->es;
+	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
 
-	return !xdiff_compare_lines(a->es->line, a->es->len,
-				    b->es->line, b->es->len,
-				    flags);
+	return !xdiff_compare_lines(a->line + a->indent_off,
+				    a->len - a->indent_off,
+				    b->line + b->indent_off,
+				    b->len - b->indent_off, flags);
 }
 
 static struct moved_entry *prepare_entry(struct diff_options *o,
@@ -945,7 +923,8 @@ static struct moved_entry *prepare_entry(struct diff_options *o,
 	struct moved_entry *ret = xmalloc(sizeof(*ret));
 	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
-	unsigned int hash = xdiff_hash_string(l->line, l->len, flags);
+	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
+					      l->len - l->indent_off, flags);
 
 	hashmap_entry_init(&ret->ent, hash);
 	ret->es = l;
@@ -1113,14 +1092,11 @@ static void mark_color_as_moved(struct diff_options *o,
 			hashmap_for_each_entry_from(hm, match, ent) {
 				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 				if (o->color_moved_ws_handling &
-				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-					if (compute_ws_delta(l, match->es,
-							     &pmb[pmb_nr].wsd))
-						pmb[pmb_nr++].match = match;
-				} else {
+				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+					pmb[pmb_nr].wsd = compute_ws_delta(l, match->es);
+				else
 					pmb[pmb_nr].wsd = 0;
-					pmb[pmb_nr++].match = match;
-				}
+				pmb[pmb_nr++].match = match;
 			}
 
 			if (adjust_last_block(o, n, block_length) &&
@@ -6240,10 +6216,6 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 		if (o->color_moved) {
 			struct hashmap add_lines, del_lines;
 
-			if (o->color_moved_ws_handling &
-			    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-				o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
-
 			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
 			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
 

diff --git a/diff.c b/diff.c
index 31a20a34240..2956c8f7103 100644
--- a/diff.c
+++ b/diff.c
@@ -18,6 +18,7 @@
 #include "submodule-config.h"
 #include "submodule.h"
 #include "hashmap.h"
+#include "mem-pool.h"
 #include "ll-merge.h"
 #include "string-list.h"
 #include "strvec.h"
@@ -772,6 +773,7 @@ struct emitted_diff_symbol {
 	int flags;
 	int indent_off;   /* Offset to first non-whitespace character */
 	int indent_width; /* The visual width of the indentation */
+	unsigned id;
 	enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -797,9 +799,9 @@ static void append_emitted_diff_symbol(struct diff_options *o,
 }
 
 struct moved_entry {
-	struct hashmap_entry ent;
 	const struct emitted_diff_symbol *es;
 	struct moved_entry *next_line;
+	struct moved_entry *next_match;
 };
 
 struct moved_block {
@@ -866,24 +868,24 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 				 const struct emitted_diff_symbol *l,
 				 struct moved_block *pmb)
 {
-	int al = cur->es->len, bl = l->len;
-	const char *a = cur->es->line,
-		   *b = l->line;
-	int a_off = cur->es->indent_off,
-	    a_width = cur->es->indent_width,
-	    b_off = l->indent_off,
-	    b_width = l->indent_width;
+	int a_width = cur->es->indent_width, b_width = l->indent_width;
 	int delta;
 
-	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+	/* The text of each line must match */
+	if (cur->es->id != l->id)
+		return 1;
+
+	/*
+	 * If 'l' and 'cur' are both blank then we don't need to check the
+	 * indent. We only need to check cur as we know the strings match.
+	 * */
+	if (a_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
 	 * The indent changes of the block are known and stored in pmb->wsd;
 	 * however we need to check if the indent changes of the current line
-	 * match those of the current block and that the text of 'l' and 'cur'
-	 * after the indentation match.
+	 * match those of the current block.
 	 */
 	delta = b_width - a_width;
 
@@ -894,22 +896,26 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
-		 !memcmp(a + a_off, b + b_off, al - a_off));
+	return delta != pmb->wsd;
 }
 
-static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
-			   const struct hashmap_entry *eptr,
-			   const struct hashmap_entry *entry_or_key,
-			   const void *keydata)
+struct interned_diff_symbol {
+	struct hashmap_entry ent;
+	struct emitted_diff_symbol *es;
+};
+
+static int interned_diff_symbol_cmp(const void *hashmap_cmp_fn_data,
+				    const struct hashmap_entry *eptr,
+				    const struct hashmap_entry *entry_or_key,
+				    const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
 	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent)->es;
-	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
+	a = container_of(eptr, const struct interned_diff_symbol, ent)->es;
+	b = container_of(entry_or_key, const struct interned_diff_symbol, ent)->es;
 
 	return !xdiff_compare_lines(a->line + a->indent_off,
 				    a->len - a->indent_off,
@@ -917,55 +923,81 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 				    b->len - b->indent_off, flags);
 }
 
-static struct moved_entry *prepare_entry(struct diff_options *o,
-					 int line_no)
+static void prepare_entry(struct diff_options *o, struct emitted_diff_symbol *l,
+			  struct interned_diff_symbol *s)
 {
-	struct moved_entry *ret = xmalloc(sizeof(*ret));
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
 					      l->len - l->indent_off, flags);
 
-	hashmap_entry_init(&ret->ent, hash);
-	ret->es = l;
-	ret->next_line = NULL;
-
-	return ret;
+	hashmap_entry_init(&s->ent, hash);
+	s->es = l;
 }
 
-static void add_lines_to_move_detection(struct diff_options *o,
-					struct hashmap *add_lines,
-					struct hashmap *del_lines)
+struct moved_entry_list {
+	struct moved_entry *add, *del;
+};
+
+static struct moved_entry_list *add_lines_to_move_detection(struct diff_options *o,
+							    struct mem_pool *entry_mem_pool)
 {
 	struct moved_entry *prev_line = NULL;
-
+	struct mem_pool interned_pool;
+	struct hashmap interned_map;
+	struct moved_entry_list *entry_list = NULL;
+	size_t entry_list_alloc = 0;
+	unsigned id = 0;
 	int n;
+
+	hashmap_init(&interned_map, interned_diff_symbol_cmp, o, 8096);
+	mem_pool_init(&interned_pool, 1024 * 1024);
+
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm;
-		struct moved_entry *key;
+		struct interned_diff_symbol key;
+		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+		struct interned_diff_symbol *s;
+		struct moved_entry *entry;
 
-		switch (o->emitted_symbols->buf[n].s) {
-		case DIFF_SYMBOL_PLUS:
-			hm = add_lines;
-			break;
-		case DIFF_SYMBOL_MINUS:
-			hm = del_lines;
-			break;
-		default:
+		if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS) {
 			prev_line = NULL;
 			continue;
 		}
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			fill_es_indent_data(&o->emitted_symbols->buf[n]);
-		key = prepare_entry(o, n);
-		if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
-			prev_line->next_line = key;
+			fill_es_indent_data(l);
 
-		hashmap_add(hm, &key->ent);
-		prev_line = key;
+		prepare_entry(o, l, &key);
+		s = hashmap_get_entry(&interned_map, &key, ent, &key.ent);
+		if (s) {
+			l->id = s->es->id;
+		} else {
+			l->id = id;
+			ALLOC_GROW_BY(entry_list, id, 1, entry_list_alloc);
+			hashmap_add(&interned_map,
+				    memcpy(mem_pool_alloc(&interned_pool,
+							  sizeof(key)),
+					   &key, sizeof(key)));
+		}
+		entry = mem_pool_alloc(entry_mem_pool, sizeof(*entry));
+		entry->es = l;
+		entry->next_line = NULL;
+		if (prev_line && prev_line->es->s == l->s)
+			prev_line->next_line = entry;
+		prev_line = entry;
+		if (l->s == DIFF_SYMBOL_PLUS) {
+			entry->next_match = entry_list[l->id].add;
+			entry_list[l->id].add = entry;
+		} else {
+			entry->next_match = entry_list[l->id].del;
+			entry_list[l->id].del = entry;
+		}
 	}
+
+	hashmap_clear(&interned_map);
+	mem_pool_discard(&interned_pool, 0);
+
+	return entry_list;
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
@@ -974,7 +1006,6 @@ static void pmb_advance_or_null(struct diff_options *o,
 				int *pmb_nr)
 {
 	int i, j;
-	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
@@ -987,9 +1018,8 @@ static void pmb_advance_or_null(struct diff_options *o,
 			match = cur &&
 				!cmp_in_block_with_wsd(o, cur, l, &pmb[i]);
 		else
-			match = cur &&
-				xdiff_compare_lines(cur->es->line, cur->es->len,
-						    l->line, l->len, flags);
+			match = cur && cur->es->id == l->id;
+
 		if (match)
 			pmb[j++].match = cur;
 	}
@@ -1034,8 +1064,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
 static void mark_color_as_moved(struct diff_options *o,
-				struct hashmap *add_lines,
-				struct hashmap *del_lines)
+				struct moved_entry_list *entry_list)
 {
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
@@ -1044,23 +1073,15 @@ static void mark_color_as_moved(struct diff_options *o,
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm = NULL;
-		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
-			hm = del_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].del;
 			break;
 		case DIFF_SYMBOL_MINUS:
-			hm = add_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].add;
 			break;
 		default:
 			flipped_block = 0;
@@ -1089,7 +1110,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			 * The current line is the start of a new block.
 			 * Setup the set of potential blocks.
 			 */
-			hashmap_for_each_entry_from(hm, match, ent) {
+			for (; match; match = match->next_match) {
 				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 				if (o->color_moved_ws_handling &
 				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -6216,20 +6237,18 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 
 	if (o->emitted_symbols) {
 		if (o->color_moved) {
-			struct hashmap add_lines, del_lines;
-
-			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
-			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
+			struct mem_pool entry_pool;
+			struct moved_entry_list *entry_list;
 
-			add_lines_to_move_detection(o, &add_lines, &del_lines);
-			mark_color_as_moved(o, &add_lines, &del_lines);
+			mem_pool_init(&entry_pool, 1024 * 1024);
+			entry_list = add_lines_to_move_detection(o,
+								 &entry_pool);
+			mark_color_as_moved(o, entry_list);
 			if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
 				dim_moved_lines(o);
 
-			hashmap_clear_and_free(&add_lines, struct moved_entry,
-						ent);
-			hashmap_clear_and_free(&del_lines, struct moved_entry,
-						ent);
+			mem_pool_discard(&entry_pool, 0);
+			free(entry_list);
 		}
 
 		for (i = 0; i < esm.nr; i++)

diff --git a/t/perf/p4002-diff-color-moved.sh b/t/perf/p4002-diff-color-moved.sh
new file mode 100755
index 00000000000..ad56bcb71e4
--- /dev/null
+++ b/t/perf/p4002-diff-color-moved.sh
@@ -0,0 +1,45 @@
+#!/bin/sh
+
+test_description='Tests diff --color-moved performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+if ! git rev-parse --verify v2.29.0^{commit} >/dev/null
+then
+	skip_all='skipping because tag v2.29.0 was not found'
+	test_done
+fi
+
+GIT_PAGER_IN_USE=1
+test_export GIT_PAGER_IN_USE
+
+test_perf 'diff --no-color-moved --no-color-moved-ws large change' '
+	git diff --no-color-moved --no-color-moved-ws v2.28.0 v2.29.0
+'
+
+test_perf 'diff --color-moved --no-color-moved-ws large change' '
+	git diff --color-moved=zebra --no-color-moved-ws v2.28.0 v2.29.0
+'
+
+test_perf 'diff --color-moved-ws=allow-indentation-change large change' '
+	git diff --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		v2.28.0 v2.29.0
+'
+
+test_perf 'log --no-color-moved --no-color-moved-ws' '
+	git log --no-color-moved --no-color-moved-ws --no-merges --patch \
+		-n1000 v2.29.0
+'
+
+test_perf 'log --color-moved --no-color-moved-ws' '
+	git log --color-moved=zebra --no-color-moved-ws --no-merges --patch \
+		-n1000 v2.29.0
+'
+
+test_perf 'log --color-moved-ws=allow-indentation-change' '
+	git log --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		--no-merges --patch -n1000 v2.29.0
+'
+
+test_done

diff --git a/diff.c b/diff.c
index 52c791574b7..bd8e4ec9757 100644
--- a/diff.c
+++ b/diff.c
@@ -1114,6 +1114,8 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
  * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
  * Think of a way to unify them.
  */
+#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
+  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 static int adjust_last_block(struct diff_options *o, int n, int block_length)
 {
 	int i, alnum_count = 0;
@@ -1130,7 +1132,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 		}
 	}
 	for (i = 1; i < block_length + 1; i++)
-		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK;
 	return 0;
 }
 
@@ -1237,8 +1239,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	free(pmb);
 }
 
-#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
-  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 static void dim_moved_lines(struct diff_options *o)
 {
 	int n;

diff --git a/diff.c b/diff.c
index bd8e4ec9757..09af94e018c 100644
--- a/diff.c
+++ b/diff.c
@@ -1098,6 +1098,38 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
 	return rp + 1;
 }
 
+static void fill_potential_moved_blocks(struct diff_options *o,
+					struct hashmap *hm,
+					struct moved_entry *match,
+					struct emitted_diff_symbol *l,
+					struct moved_block **pmb_p,
+					int *pmb_alloc_p, int *pmb_nr_p)
+
+{
+	struct moved_block *pmb = *pmb_p;
+	int pmb_alloc = *pmb_alloc_p, pmb_nr = *pmb_nr_p;
+
+	/*
+	 * The current line is the start of a new block.
+	 * Setup the set of potential blocks.
+	 */
+	hashmap_for_each_entry_from(hm, match, ent) {
+		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
+			if (compute_ws_delta(l, match->es, &(pmb[pmb_nr]).wsd))
+				pmb[pmb_nr++].match = match;
+		} else {
+			pmb[pmb_nr].wsd = 0;
+			pmb[pmb_nr++].match = match;
+		}
+	}
+
+	*pmb_p = pmb;
+	*pmb_alloc_p = pmb_alloc;
+	*pmb_nr_p = pmb_nr;
+}
+
 /*
  * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
  *
@@ -1198,23 +1230,8 @@ static void mark_color_as_moved(struct diff_options *o,
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
 		if (pmb_nr == 0) {
-			/*
-			 * The current line is the start of a new block.
-			 * Setup the set of potential blocks.
-			 */
-			hashmap_for_each_entry_from(hm, match, ent) {
-				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
-				if (o->color_moved_ws_handling &
-				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-					if (compute_ws_delta(l, match->es,
-							     &pmb[pmb_nr].wsd))
-						pmb[pmb_nr++].match = match;
-				} else {
-					pmb[pmb_nr].wsd = 0;
-					pmb[pmb_nr++].match = match;
-				}
-			}
-
+			fill_potential_moved_blocks(
+				o, hm, match, l, &pmb, &pmb_alloc, &pmb_nr);
 			if (adjust_last_block(o, n, block_length) &&
 			    pmb_nr && last_symbol != l->s)
 				flipped_block = (flipped_block + 1) % 2;

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 09af94e018c..1e1b5127d15 100644
--- a/diff.c
+++ b/diff.c
@@ -1205,7 +1205,15 @@ static void mark_color_as_moved(struct diff_options *o,
 		if (!match) {
 			int i;
 
-			adjust_last_block(o, n, block_length);
+			if (!adjust_last_block(o, n, block_length) &&
+			    block_length > 1) {
+				/*
+				 * Rewind in case there is another match
+				 * starting at the second line of the block
+				 */
+				match = NULL;
+				n -= block_length;
+			}
 			for(i = 0; i < pmb_nr; i++)
 				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
@@ -1230,10 +1238,20 @@ static void mark_color_as_moved(struct diff_options *o,
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
 		if (pmb_nr == 0) {
-			fill_potential_moved_blocks(
-				o, hm, match, l, &pmb, &pmb_alloc, &pmb_nr);
-			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol != l->s)
+			int contiguous = adjust_last_block(o, n, block_length);
+
+			if (!contiguous && block_length > 1)
+				/*
+				 * Rewind in case there is another match
+				 * starting at the second line of the block
+				 */
+				n -= block_length;
+			else
+				fill_potential_moved_blocks(o, hm, match, l,
+							    &pmb, &pmb_alloc,
+							    &pmb_nr);
+
+			if (contiguous && pmb_nr && last_symbol != l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 2c13b62d3c6..308dc136596 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1833,6 +1833,52 @@ test_expect_success '--color-moved treats adjacent blocks as separate for MIN_AL
 	test_cmp expected actual
 '
 
+test_expect_success '--color-moved rewinds for MIN_ALNUM_COUNT' '
+	git reset --hard &&
+	test_write_lines >file \
+		A B C one two three four five six seven D E F G H I J &&
+	git add file &&
+	test_write_lines >file \
+		one two A B C D E F G H I J two three four five six seven &&
+	git diff --color-moved=zebra -- file &&
+
+	git diff --color-moved=zebra --color -- file >actual.raw &&
+	grep -v "index" actual.raw | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/file b/file<RESET>
+	<BOLD>--- a/file<RESET>
+	<BOLD>+++ b/file<RESET>
+	<CYAN>@@ -1,13 +1,8 @@<RESET>
+	<GREEN>+<RESET><GREEN>one<RESET>
+	<GREEN>+<RESET><GREEN>two<RESET>
+	 A<RESET>
+	 B<RESET>
+	 C<RESET>
+	<RED>-one<RESET>
+	<BOLD;MAGENTA>-two<RESET>
+	<BOLD;MAGENTA>-three<RESET>
+	<BOLD;MAGENTA>-four<RESET>
+	<BOLD;MAGENTA>-five<RESET>
+	<BOLD;MAGENTA>-six<RESET>
+	<BOLD;MAGENTA>-seven<RESET>
+	 D<RESET>
+	 E<RESET>
+	 F<RESET>
+	<CYAN>@@ -15,3 +10,9 @@<RESET> <RESET>G<RESET>
+	 H<RESET>
+	 I<RESET>
+	 J<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>two<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>three<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>four<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>five<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>six<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>seven<RESET>
+	EOF
+
+	test_cmp expected actual
+'
+
 test_expect_success 'move detection with submodules' '
 	test_create_repo bananas &&
 	echo ripe >bananas/recipe &&

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 1e1b5127d15..53f0df75329 100644
--- a/diff.c
+++ b/diff.c
@@ -1176,6 +1176,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
+	enum diff_symbol last_symbol = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1183,7 +1184,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-		enum diff_symbol last_symbol = 0;
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
@@ -1251,7 +1251,7 @@ static void mark_color_as_moved(struct diff_options *o,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
-			if (contiguous && pmb_nr && last_symbol != l->s)
+			if (contiguous && pmb_nr && last_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 308dc136596..4e0fd76c6c5 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1442,6 +1442,78 @@ test_expect_success 'detect permutations inside moved code -- dimmed-zebra' '
 	test_cmp expected actual
 '
 
+test_expect_success 'zebra alternate color is only used when necessary' '
+	cat >old.txt <<-\EOF &&
+	line 1A should be marked as oldMoved newMovedAlternate
+	line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	line 2A should be marked as oldMoved newMovedAlternate
+	line 2B should be marked as oldMoved newMovedAlternate
+	line 3A should be marked as oldMovedAlternate newMoved
+	line 3B should be marked as oldMovedAlternate newMoved
+	unchanged
+	line 4A should be marked as oldMoved newMovedAlternate
+	line 4B should be marked as oldMoved newMovedAlternate
+	line 5A should be marked as oldMovedAlternate newMoved
+	line 5B should be marked as oldMovedAlternate newMoved
+	line 6A should be marked as oldMoved newMoved
+	line 6B should be marked as oldMoved newMoved
+	EOF
+	cat >new.txt <<-\EOF &&
+	  line 1A should be marked as oldMoved newMovedAlternate
+	  line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 3A should be marked as oldMovedAlternate newMoved
+	  line 3B should be marked as oldMovedAlternate newMoved
+	  line 2A should be marked as oldMoved newMovedAlternate
+	  line 2B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 6A should be marked as oldMoved newMoved
+	  line 6B should be marked as oldMoved newMoved
+	    line 4A should be marked as oldMoved newMovedAlternate
+	    line 4B should be marked as oldMoved newMovedAlternate
+	  line 5A should be marked as oldMovedAlternate newMoved
+	  line 5B should be marked as oldMovedAlternate newMoved
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		 --color-moved-ws=allow-indentation-change \
+		 old.txt new.txt >output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,14 +1,14 @@<RESET>
+	<BOLD;MAGENTA>-line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;MAGENTA>-line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;MAGENTA>-line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 53f0df75329..efba2789354 100644
--- a/diff.c
+++ b/diff.c
@@ -1176,7 +1176,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
-	enum diff_symbol last_symbol = 0;
+	enum diff_symbol moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1202,7 +1202,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			flipped_block = 0;
 		}
 
-		if (!match) {
+		if (pmb_nr && (!match || l->s != moved_symbol)) {
 			int i;
 
 			if (!adjust_last_block(o, n, block_length) &&
@@ -1219,12 +1219,13 @@ static void mark_color_as_moved(struct diff_options *o,
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
-			last_symbol = l->s;
+		}
+		if (!match) {
+			moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 			continue;
 		}
 
 		if (o->color_moved == COLOR_MOVED_PLAIN) {
-			last_symbol = l->s;
 			l->flags |= DIFF_SYMBOL_MOVED_LINE;
 			continue;
 		}
@@ -1251,11 +1252,16 @@ static void mark_color_as_moved(struct diff_options *o,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
-			if (contiguous && pmb_nr && last_symbol == l->s)
+			if (contiguous && pmb_nr && moved_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
 
+			if (pmb_nr)
+				moved_symbol = l->s;
+			else
+				moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
+
 			block_length = 0;
 		}
 
@@ -1265,7 +1271,6 @@ static void mark_color_as_moved(struct diff_options *o,
 			if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 				l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 		}
-		last_symbol = l->s;
 	}
 	adjust_last_block(o, n, block_length);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 4e0fd76c6c5..15782c879d2 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1514,6 +1514,71 @@ test_expect_success 'zebra alternate color is only used when necessary' '
 	test_cmp expected actual
 '
 
+test_expect_success 'short lines of opposite sign do not get marked as moved' '
+	cat >old.txt <<-\EOF &&
+	this line should be marked as moved
+	unchanged
+	unchanged
+	unchanged
+	unchanged
+	too short
+	this line should be marked as oldMoved newMoved
+	this line should be marked as oldMovedAlternate newMoved
+	unchanged 1
+	unchanged 2
+	unchanged 3
+	unchanged 4
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	EOF
+	cat >new.txt <<-\EOF &&
+	too short
+	unchanged
+	unchanged
+	this line should be marked as moved
+	too short
+	unchanged
+	unchanged
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 1
+	unchanged 2
+	this line should be marked as oldMovedAlternate newMoved
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 3
+	this line should be marked as oldMoved newMoved
+	unchanged 4
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		old.txt new.txt >output && cat output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expect <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,13 +1,15 @@<RESET>
+	<BOLD;MAGENTA>-this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<RED>-too short<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved<RESET>
+	<BOLD;BLUE>-this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 1<RESET>
+	 unchanged 2<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 3<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved<RESET>
+	 unchanged 4<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/diff.c b/diff.c
index efba2789354..9aff167be27 100644
--- a/diff.c
+++ b/diff.c
@@ -864,23 +864,17 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	    a_width = a->indent_width,
 	    b_off = b->indent_off,
 	    b_width = b->indent_width;
-	int delta;
 
 	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 		*out = INDENT_BLANKLINE;
 		return 1;
 	}
 
-	if (a->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - b_width;
-	else
-		delta = b_width - a_width;
-
 	if (a_len - a_off != b_len - b_off ||
 	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 		return 0;
 
-	*out = delta;
+	*out = a_width - b_width;
 
 	return 1;
 }
@@ -924,10 +918,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	if (cur->es->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - c_width;
-	else
-		delta = c_width - a_width;
+	delta = c_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its

diff --git a/diff.c b/diff.c
index 9aff167be27..78a486021ab 100644
--- a/diff.c
+++ b/diff.c
@@ -879,37 +879,21 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	return 1;
 }
 
-static int cmp_in_block_with_wsd(const struct diff_options *o,
-				 const struct moved_entry *cur,
-				 const struct moved_entry *match,
-				 struct moved_block *pmb,
-				 int n)
-{
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-	int al = cur->es->len, bl = match->es->len, cl = l->len;
+static int cmp_in_block_with_wsd(const struct moved_entry *cur,
+				 const struct emitted_diff_symbol *l,
+				 struct moved_block *pmb)
+{
+	int al = cur->es->len, bl = l->len;
 	const char *a = cur->es->line,
-		   *b = match->es->line,
-		   *c = l->line;
+		   *b = l->line;
 	int a_off = cur->es->indent_off,
 	    a_width = cur->es->indent_width,
-	    c_off = l->indent_off,
-	    c_width = l->indent_width;
+	    b_off = l->indent_off,
+	    b_width = l->indent_width;
 	int delta;
 
-	/*
-	 * We need to check if 'cur' is equal to 'match'.  As those
-	 * are from the same (+/-) side, we do not need to adjust for
-	 * indent changes. However these were found using fuzzy
-	 * matching so we do have to check if they are equal. Here we
-	 * just check the lengths. We delay calling memcmp() to check
-	 * the contents until later as if the length comparison for a
-	 * and c fails we can avoid the call all together.
-	 */
-	if (al != bl)
-		return 1;
-
 	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
@@ -918,7 +902,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	delta = c_width - a_width;
+	delta = b_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its
@@ -927,9 +911,8 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == cl - c_off &&
-		 !memcmp(a, b, al) && !
-		 memcmp(a + a_off, c + c_off, al - a_off));
+	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
+		 !memcmp(a + a_off, b + b_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -1030,36 +1013,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct moved_entry *match,
-					    struct hashmap *hm,
+					    struct emitted_diff_symbol *l,
 					    struct moved_block *pmb,
-					    int pmb_nr, int n)
+					    int pmb_nr)
 {
 	int i;
-	char *got_match = xcalloc(1, pmb_nr);
-
-	hashmap_for_each_entry_from(hm, match, ent) {
-		for (i = 0; i < pmb_nr; i++) {
-			struct moved_entry *prev = pmb[i].match;
-			struct moved_entry *cur = (prev && prev->next_line) ?
-					prev->next_line : NULL;
-			if (!cur)
-				continue;
-			if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
-				got_match[i] |= 1;
-		}
-	}
 
 	for (i = 0; i < pmb_nr; i++) {
-		if (got_match[i]) {
+		struct moved_entry *prev = pmb[i].match;
+		struct moved_entry *cur = (prev && prev->next_line) ?
+			prev->next_line : NULL;
+		if (cur && !cmp_in_block_with_wsd(cur, l, &pmb[i])) {
 			/* Advance to the next line */
-			pmb[i].match = pmb[i].match->next_line;
+			pmb[i].match = cur;
 		} else {
 			moved_block_clear(&pmb[i]);
 		}
 	}
-
-	free(got_match);
 }
 
 static int shrink_potential_moved_blocks(struct moved_block *pmb,
@@ -1223,7 +1193,7 @@ static void mark_color_as_moved(struct diff_options *o,
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
+			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
 			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 78a486021ab..22e0edac173 100644
--- a/diff.c
+++ b/diff.c
@@ -994,17 +994,20 @@ static void add_lines_to_move_detection(struct diff_options *o,
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
-				struct moved_entry *match,
-				struct hashmap *hm,
+				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
 				int pmb_nr)
 {
 	int i;
+	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
+
 	for (i = 0; i < pmb_nr; i++) {
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && !hm->cmpfn(o, &cur->ent, &match->ent, NULL)) {
+		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
+						l->line, l->len,
+						flags)) {
 			pmb[i].match = cur;
 		} else {
 			pmb[i].match = NULL;
@@ -1195,7 +1198,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
-			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
+			pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 22e0edac173..51f092e724e 100644
--- a/diff.c
+++ b/diff.c
@@ -1002,36 +1002,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0; i < pmb_nr; i++) {
+		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
-						l->line, l->len,
-						flags)) {
-			pmb[i].match = cur;
-		} else {
-			pmb[i].match = NULL;
-		}
-	}
-}
 
-static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct emitted_diff_symbol *l,
-					    struct moved_block *pmb,
-					    int pmb_nr)
-{
-	int i;
-
-	for (i = 0; i < pmb_nr; i++) {
-		struct moved_entry *prev = pmb[i].match;
-		struct moved_entry *cur = (prev && prev->next_line) ?
-			prev->next_line : NULL;
-		if (cur && !cmp_in_block_with_wsd(cur, l, &pmb[i])) {
-			/* Advance to the next line */
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			match = cur &&
+				!cmp_in_block_with_wsd(cur, l, &pmb[i]);
+		else
+			match = cur &&
+				xdiff_compare_lines(cur->es->line, cur->es->len,
+						    l->line, l->len, flags);
+		if (match)
 			pmb[i].match = cur;
-		} else {
+		else
 			moved_block_clear(&pmb[i]);
-		}
 	}
 }
 
@@ -1194,11 +1181,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
-		else
-			pmb_advance_or_null(o, l, pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 51f092e724e..626fd47aa0e 100644
--- a/diff.c
+++ b/diff.c
@@ -996,12 +996,12 @@ static void add_lines_to_move_detection(struct diff_options *o,
 static void pmb_advance_or_null(struct diff_options *o,
 				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
-				int pmb_nr)
+				int *pmb_nr)
 {
-	int i;
+	int i, j;
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
-	for (i = 0; i < pmb_nr; i++) {
+	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
@@ -1015,38 +1015,12 @@ static void pmb_advance_or_null(struct diff_options *o,
 			match = cur &&
 				xdiff_compare_lines(cur->es->line, cur->es->len,
 						    l->line, l->len, flags);
-		if (match)
-			pmb[i].match = cur;
-		else
-			moved_block_clear(&pmb[i]);
-	}
-}
-
-static int shrink_potential_moved_blocks(struct moved_block *pmb,
-					 int pmb_nr)
-{
-	int lp, rp;
-
-	/* Shrink the set of potential block to the remaining running */
-	for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
-		while (lp < pmb_nr && pmb[lp].match)
-			lp++;
-		/* lp points at the first NULL now */
-
-		while (rp > -1 && !pmb[rp].match)
-			rp--;
-		/* rp points at the last non-NULL */
-
-		if (lp < pmb_nr && rp > -1 && lp < rp) {
-			pmb[lp] = pmb[rp];
-			memset(&pmb[rp], 0, sizeof(pmb[rp]));
-			rp--;
-			lp++;
+		if (match) {
+			pmb[j] = pmb[i];
+			pmb[j++].match = cur;
 		}
 	}
-
-	/* Remember the number of running sets */
-	return rp + 1;
+	*pmb_nr = j;
 }
 
 static void fill_potential_moved_blocks(struct diff_options *o,
@@ -1181,9 +1155,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		pmb_advance_or_null(o, l, pmb, pmb_nr);
-
-		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, &pmb_nr);
 
 		if (pmb_nr == 0) {
 			int contiguous = adjust_last_block(o, n, block_length);

diff --git a/diff.c b/diff.c
index 626fd47aa0e..ffbe09937bc 100644
--- a/diff.c
+++ b/diff.c
@@ -807,11 +807,6 @@ struct moved_block {
 	int wsd; /* The whitespace delta of this block */
 };
 
-static void moved_block_clear(struct moved_block *b)
-{
-	memset(b, 0, sizeof(*b));
-}
-
 #define INDENT_BLANKLINE INT_MIN
 
 static void fill_es_indent_data(struct emitted_diff_symbol *es)
@@ -1128,8 +1123,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		}
 
 		if (pmb_nr && (!match || l->s != moved_symbol)) {
-			int i;
-
 			if (!adjust_last_block(o, n, block_length) &&
 			    block_length > 1) {
 				/*
@@ -1139,8 +1132,6 @@ static void mark_color_as_moved(struct diff_options *o,
 				match = NULL;
 				n -= block_length;
 			}
-			for(i = 0; i < pmb_nr; i++)
-				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
@@ -1193,8 +1184,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	}
 	adjust_last_block(o, n, block_length);
 
-	for(n = 0; n < pmb_nr; n++)
-		moved_block_clear(&pmb[n]);
 	free(pmb);
 }
 

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index ffbe09937bc..2085c063675 100644
--- a/diff.c
+++ b/diff.c
@@ -850,28 +850,15 @@ static void fill_es_indent_data(struct emitted_diff_symbol *es)
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
-			    const struct emitted_diff_symbol *b,
-			    int *out)
-{
-	int a_len = a->len,
-	    b_len = b->len,
-	    a_off = a->indent_off,
-	    a_width = a->indent_width,
-	    b_off = b->indent_off,
+			    const struct emitted_diff_symbol *b)
+{
+	int a_width = a->indent_width,
 	    b_width = b->indent_width;
 
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
-		*out = INDENT_BLANKLINE;
-		return 1;
-	}
-
-	if (a_len - a_off != b_len - b_off ||
-	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
-		return 0;
-
-	*out = a_width - b_width;
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+		return INDENT_BLANKLINE;
 
-	return 1;
+	return a_width - b_width;
 }
 
 static int cmp_in_block_with_wsd(const struct moved_entry *cur,
@@ -916,26 +903,17 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 			   const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
-	const struct moved_entry *a, *b;
+	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent);
-	b = container_of(entry_or_key, const struct moved_entry, ent);
+	a = container_of(eptr, const struct moved_entry, ent)->es;
+	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
 
-	if (diffopt->color_moved_ws_handling &
-	    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-		/*
-		 * As there is not specific white space config given,
-		 * we'd need to check for a new block, so ignore all
-		 * white space. The setup of the white space
-		 * configuration for the next block is done else where
-		 */
-		flags |= XDF_IGNORE_WHITESPACE;
-
-	return !xdiff_compare_lines(a->es->line, a->es->len,
-				    b->es->line, b->es->len,
-				    flags);
+	return !xdiff_compare_lines(a->line + a->indent_off,
+				    a->len - a->indent_off,
+				    b->line + b->indent_off,
+				    b->len - b->indent_off, flags);
 }
 
 static struct moved_entry *prepare_entry(struct diff_options *o,
@@ -944,7 +922,8 @@ static struct moved_entry *prepare_entry(struct diff_options *o,
 	struct moved_entry *ret = xmalloc(sizeof(*ret));
 	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
-	unsigned int hash = xdiff_hash_string(l->line, l->len, flags);
+	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
+					      l->len - l->indent_off, flags);
 
 	hashmap_entry_init(&ret->ent, hash);
 	ret->es = l;
@@ -1036,13 +1015,11 @@ static void fill_potential_moved_blocks(struct diff_options *o,
 	hashmap_for_each_entry_from(hm, match, ent) {
 		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-			if (compute_ws_delta(l, match->es, &(pmb[pmb_nr]).wsd))
-				pmb[pmb_nr++].match = match;
-		} else {
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			pmb[pmb_nr].wsd = compute_ws_delta(l, match->es);
+		else
 			pmb[pmb_nr].wsd = 0;
-			pmb[pmb_nr++].match = match;
-		}
+		pmb[pmb_nr++].match = match;
 	}
 
 	*pmb_p = pmb;
@@ -6276,10 +6253,6 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 		if (o->color_moved) {
 			struct hashmap add_lines, del_lines;
 
-			if (o->color_moved_ws_handling &
-			    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-				o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
-
 			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
 			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 15782c879d2..50d0cf486be 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -2206,10 +2206,10 @@ EMPTY=''
 test_expect_success 'compare mixed whitespace delta across moved blocks' '
 
 	git reset --hard &&
-	tr Q_ "\t " <<-EOF >text.txt &&
-	${EMPTY}
-	____too short without
-	${EMPTY}
+	tr "^|Q_" "\f\v\t " <<-EOF >text.txt &&
+	^__
+	|____too short without
+	^
 	___being grouped across blank line
 	${EMPTY}
 	context
@@ -2228,7 +2228,7 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 	git add text.txt &&
 	git commit -m "add text.txt" &&
 
-	tr Q_ "\t " <<-EOF >text.txt &&
+	tr "^|Q_" "\f\v\t " <<-EOF >text.txt &&
 	context
 	lines
 	to
@@ -2239,7 +2239,7 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 	${EMPTY}
 	QQtoo short without
 	${EMPTY}
-	Q_______being grouped across blank line
+	^Q_______being grouped across blank line
 	${EMPTY}
 	Q_QThese two lines have had their
 	indentation reduced by four spaces
@@ -2251,16 +2251,16 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 		-c core.whitespace=space-before-tab \
 		diff --color --color-moved --ws-error-highlight=all \
 		--color-moved-ws=allow-indentation-change >actual.raw &&
-	grep -v "index" actual.raw | test_decode_color >actual &&
+	grep -v "index" actual.raw | tr "\f\v" "^|" | test_decode_color >actual &&
 
 	cat <<-\EOF >expected &&
 	<BOLD>diff --git a/text.txt b/text.txt<RESET>
 	<BOLD>--- a/text.txt<RESET>
 	<BOLD>+++ b/text.txt<RESET>
 	<CYAN>@@ -1,16 +1,16 @@<RESET>
-	<BOLD;MAGENTA>-<RESET>
-	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>    too short without<RESET>
-	<BOLD;MAGENTA>-<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>^<RESET><BRED>  <RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>|    too short without<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>^<RESET>
 	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>   being grouped across blank line<RESET>
 	<BOLD;MAGENTA>-<RESET>
 	 <RESET>context<RESET>
@@ -2280,7 +2280,7 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 	<BOLD;YELLOW>+<RESET>
 	<BOLD;YELLOW>+<RESET>		<BOLD;YELLOW>too short without<RESET>
 	<BOLD;YELLOW>+<RESET>
-	<BOLD;YELLOW>+<RESET>	<BOLD;YELLOW>       being grouped across blank line<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>^	       being grouped across blank line<RESET>
 	<BOLD;YELLOW>+<RESET>
 	<BOLD;CYAN>+<RESET>	<BRED> <RESET>	<BOLD;CYAN>These two lines have had their<RESET>
 	<BOLD;CYAN>+<RESET><BOLD;CYAN>indentation reduced by four spaces<RESET>

diff --git a/diff.c b/diff.c
index 2085c063675..9ef88d7665a 100644
--- a/diff.c
+++ b/diff.c
@@ -1497,7 +1497,9 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len, unsigned flags)
 {
-	struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
+	struct emitted_diff_symbol e = {
+		.line = line, .len = len, .flags = flags, .s = s
+	};
 
 	if (o->emitted_symbols)
 		append_emitted_diff_symbol(o, &e);

diff --git a/diff.c b/diff.c
index 9ef88d7665a..c28c56c1283 100644
--- a/diff.c
+++ b/diff.c
@@ -18,6 +18,7 @@
 #include "submodule-config.h"
 #include "submodule.h"
 #include "hashmap.h"
+#include "mem-pool.h"
 #include "ll-merge.h"
 #include "string-list.h"
 #include "strvec.h"
@@ -772,6 +773,7 @@ struct emitted_diff_symbol {
 	int flags;
 	int indent_off;   /* Offset to first non-whitespace character */
 	int indent_width; /* The visual width of the indentation */
+	unsigned id;
 	enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -797,9 +799,9 @@ static void append_emitted_diff_symbol(struct diff_options *o,
 }
 
 struct moved_entry {
-	struct hashmap_entry ent;
 	const struct emitted_diff_symbol *es;
 	struct moved_entry *next_line;
+	struct moved_entry *next_match;
 };
 
 struct moved_block {
@@ -865,24 +867,24 @@ static int cmp_in_block_with_wsd(const struct moved_entry *cur,
 				 const struct emitted_diff_symbol *l,
 				 struct moved_block *pmb)
 {
-	int al = cur->es->len, bl = l->len;
-	const char *a = cur->es->line,
-		   *b = l->line;
-	int a_off = cur->es->indent_off,
-	    a_width = cur->es->indent_width,
-	    b_off = l->indent_off,
-	    b_width = l->indent_width;
+	int a_width = cur->es->indent_width, b_width = l->indent_width;
 	int delta;
 
-	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+	/* The text of each line must match */
+	if (cur->es->id != l->id)
+		return 1;
+
+	/*
+	 * If 'l' and 'cur' are both blank then we don't need to check the
+	 * indent. We only need to check cur as we know the strings match.
+	 * */
+	if (a_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
 	 * The indent changes of the block are known and stored in pmb->wsd;
 	 * however we need to check if the indent changes of the current line
-	 * match those of the current block and that the text of 'l' and 'cur'
-	 * after the indentation match.
+	 * match those of the current block.
 	 */
 	delta = b_width - a_width;
 
@@ -893,22 +895,26 @@ static int cmp_in_block_with_wsd(const struct moved_entry *cur,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
-		 !memcmp(a + a_off, b + b_off, al - a_off));
+	return delta != pmb->wsd;
 }
 
-static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
-			   const struct hashmap_entry *eptr,
-			   const struct hashmap_entry *entry_or_key,
-			   const void *keydata)
+struct interned_diff_symbol {
+	struct hashmap_entry ent;
+	struct emitted_diff_symbol *es;
+};
+
+static int interned_diff_symbol_cmp(const void *hashmap_cmp_fn_data,
+				    const struct hashmap_entry *eptr,
+				    const struct hashmap_entry *entry_or_key,
+				    const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
 	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent)->es;
-	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
+	a = container_of(eptr, const struct interned_diff_symbol, ent)->es;
+	b = container_of(entry_or_key, const struct interned_diff_symbol, ent)->es;
 
 	return !xdiff_compare_lines(a->line + a->indent_off,
 				    a->len - a->indent_off,
@@ -916,55 +922,81 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 				    b->len - b->indent_off, flags);
 }
 
-static struct moved_entry *prepare_entry(struct diff_options *o,
-					 int line_no)
+static void prepare_entry(struct diff_options *o, struct emitted_diff_symbol *l,
+			  struct interned_diff_symbol *s)
 {
-	struct moved_entry *ret = xmalloc(sizeof(*ret));
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
 					      l->len - l->indent_off, flags);
 
-	hashmap_entry_init(&ret->ent, hash);
-	ret->es = l;
-	ret->next_line = NULL;
-
-	return ret;
+	hashmap_entry_init(&s->ent, hash);
+	s->es = l;
 }
 
-static void add_lines_to_move_detection(struct diff_options *o,
-					struct hashmap *add_lines,
-					struct hashmap *del_lines)
+struct moved_entry_list {
+	struct moved_entry *add, *del;
+};
+
+static struct moved_entry_list *add_lines_to_move_detection(struct diff_options *o,
+							    struct mem_pool *entry_mem_pool)
 {
 	struct moved_entry *prev_line = NULL;
-
+	struct mem_pool interned_pool;
+	struct hashmap interned_map;
+	struct moved_entry_list *entry_list = NULL;
+	size_t entry_list_alloc = 0;
+	unsigned id = 0;
 	int n;
+
+	hashmap_init(&interned_map, interned_diff_symbol_cmp, o, 8096);
+	mem_pool_init(&interned_pool, 1024 * 1024);
+
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm;
-		struct moved_entry *key;
+		struct interned_diff_symbol key;
+		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+		struct interned_diff_symbol *s;
+		struct moved_entry *entry;
 
-		switch (o->emitted_symbols->buf[n].s) {
-		case DIFF_SYMBOL_PLUS:
-			hm = add_lines;
-			break;
-		case DIFF_SYMBOL_MINUS:
-			hm = del_lines;
-			break;
-		default:
+		if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS) {
 			prev_line = NULL;
 			continue;
 		}
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			fill_es_indent_data(&o->emitted_symbols->buf[n]);
-		key = prepare_entry(o, n);
-		if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
-			prev_line->next_line = key;
+			fill_es_indent_data(l);
 
-		hashmap_add(hm, &key->ent);
-		prev_line = key;
+		prepare_entry(o, l, &key);
+		s = hashmap_get_entry(&interned_map, &key, ent, &key.ent);
+		if (s) {
+			l->id = s->es->id;
+		} else {
+			l->id = id;
+			ALLOC_GROW_BY(entry_list, id, 1, entry_list_alloc);
+			hashmap_add(&interned_map,
+				    memcpy(mem_pool_alloc(&interned_pool,
+							  sizeof(key)),
+					   &key, sizeof(key)));
+		}
+		entry = mem_pool_alloc(entry_mem_pool, sizeof(*entry));
+		entry->es = l;
+		entry->next_line = NULL;
+		if (prev_line && prev_line->es->s == l->s)
+			prev_line->next_line = entry;
+		prev_line = entry;
+		if (l->s == DIFF_SYMBOL_PLUS) {
+			entry->next_match = entry_list[l->id].add;
+			entry_list[l->id].add = entry;
+		} else {
+			entry->next_match = entry_list[l->id].del;
+			entry_list[l->id].del = entry;
+		}
 	}
+
+	hashmap_clear(&interned_map);
+	mem_pool_discard(&interned_pool, 0);
+
+	return entry_list;
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
@@ -973,7 +1005,6 @@ static void pmb_advance_or_null(struct diff_options *o,
 				int *pmb_nr)
 {
 	int i, j;
-	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
@@ -986,9 +1017,8 @@ static void pmb_advance_or_null(struct diff_options *o,
 			match = cur &&
 				!cmp_in_block_with_wsd(cur, l, &pmb[i]);
 		else
-			match = cur &&
-				xdiff_compare_lines(cur->es->line, cur->es->len,
-						    l->line, l->len, flags);
+			match = cur && cur->es->id == l->id;
+
 		if (match) {
 			pmb[j] = pmb[i];
 			pmb[j++].match = cur;
@@ -998,7 +1028,6 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void fill_potential_moved_blocks(struct diff_options *o,
-					struct hashmap *hm,
 					struct moved_entry *match,
 					struct emitted_diff_symbol *l,
 					struct moved_block **pmb_p,
@@ -1012,7 +1041,7 @@ static void fill_potential_moved_blocks(struct diff_options *o,
 	 * The current line is the start of a new block.
 	 * Setup the set of potential blocks.
 	 */
-	hashmap_for_each_entry_from(hm, match, ent) {
+	for (; match; match = match->next_match) {
 		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -1067,8 +1096,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
 static void mark_color_as_moved(struct diff_options *o,
-				struct hashmap *add_lines,
-				struct hashmap *del_lines)
+				struct moved_entry_list *entry_list)
 {
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
@@ -1077,23 +1105,15 @@ static void mark_color_as_moved(struct diff_options *o,
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm = NULL;
-		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
-			hm = del_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].del;
 			break;
 		case DIFF_SYMBOL_MINUS:
-			hm = add_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].add;
 			break;
 		default:
 			flipped_block = 0;
@@ -1135,7 +1155,7 @@ static void mark_color_as_moved(struct diff_options *o,
 				 */
 				n -= block_length;
 			else
-				fill_potential_moved_blocks(o, hm, match, l,
+				fill_potential_moved_blocks(o, match, l,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
@@ -6253,20 +6273,18 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 
 	if (o->emitted_symbols) {
 		if (o->color_moved) {
-			struct hashmap add_lines, del_lines;
-
-			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
-			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
+			struct mem_pool entry_pool;
+			struct moved_entry_list *entry_list;
 
-			add_lines_to_move_detection(o, &add_lines, &del_lines);
-			mark_color_as_moved(o, &add_lines, &del_lines);
+			mem_pool_init(&entry_pool, 1024 * 1024);
+			entry_list = add_lines_to_move_detection(o,
+								 &entry_pool);
+			mark_color_as_moved(o, entry_list);
 			if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
 				dim_moved_lines(o);
 
-			hashmap_clear_and_free(&add_lines, struct moved_entry,
-						ent);
-			hashmap_clear_and_free(&del_lines, struct moved_entry,
-						ent);
+			mem_pool_discard(&entry_pool, 0);
+			free(entry_list);
 		}
 
 		for (i = 0; i < esm.nr; i++)

diff --git a/t/perf/p4002-diff-color-moved.sh b/t/perf/p4002-diff-color-moved.sh
new file mode 100755
index 00000000000..ab2af931c04
--- /dev/null
+++ b/t/perf/p4002-diff-color-moved.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+
+test_description='Tests diff --color-moved performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+# The endpoints of the diff can be customized by setting TEST_REV_A
+# and TEST_REV_B in the environment when running this test.
+
+rev="${TEST_REV_A:-v2.28.0}"
+if ! rev_a="$(git rev-parse --quiet --verify "$rev")"
+then
+	skip_all="skipping because '$rev' was not found. \
+		  Use TEST_REV_A and TEST_REV_B to set the revs to use"
+	test_done
+fi
+rev="${TEST_REV_B:-v2.29.0}"
+if ! rev_b="$(git rev-parse --quiet --verify "$rev")"
+then
+	skip_all="skipping because '$rev' was not found. \
+		  Use TEST_REV_A and TEST_REV_B to set the revs to use"
+	test_done
+fi
+
+GIT_PAGER_IN_USE=1
+test_export GIT_PAGER_IN_USE rev_a rev_b
+
+test_perf 'diff --no-color-moved --no-color-moved-ws large change' '
+	git diff --no-color-moved --no-color-moved-ws $rev_a $rev_b
+'
+
+test_perf 'diff --color-moved --no-color-moved-ws large change' '
+	git diff --color-moved=zebra --no-color-moved-ws $rev_a $rev_b
+'
+
+test_perf 'diff --color-moved-ws=allow-indentation-change large change' '
+	git diff --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		$rev_a $rev_b
+'
+
+test_perf 'log --no-color-moved --no-color-moved-ws' '
+	git log --no-color-moved --no-color-moved-ws --no-merges --patch \
+		-n1000 $rev_b
+'
+
+test_perf 'log --color-moved --no-color-moved-ws' '
+	git log --color-moved=zebra --no-color-moved-ws --no-merges --patch \
+		-n1000 $rev_b
+'
+
+test_perf 'log --color-moved-ws=allow-indentation-change' '
+	git log --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		--no-merges --patch -n1000 $rev_b
+'
+
+test_done

diff --git a/diff.c b/diff.c
index 52c791574b7..bd8e4ec9757 100644
--- a/diff.c
+++ b/diff.c
@@ -1114,6 +1114,8 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
  * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
  * Think of a way to unify them.
  */
+#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
+  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 static int adjust_last_block(struct diff_options *o, int n, int block_length)
 {
 	int i, alnum_count = 0;
@@ -1130,7 +1132,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 		}
 	}
 	for (i = 1; i < block_length + 1; i++)
-		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK;
 	return 0;
 }
 
@@ -1237,8 +1239,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	free(pmb);
 }
 
-#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
-  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 static void dim_moved_lines(struct diff_options *o)
 {
 	int n;

diff --git a/diff.c b/diff.c
index bd8e4ec9757..09af94e018c 100644
--- a/diff.c
+++ b/diff.c
@@ -1098,6 +1098,38 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
 	return rp + 1;
 }
 
+static void fill_potential_moved_blocks(struct diff_options *o,
+					struct hashmap *hm,
+					struct moved_entry *match,
+					struct emitted_diff_symbol *l,
+					struct moved_block **pmb_p,
+					int *pmb_alloc_p, int *pmb_nr_p)
+
+{
+	struct moved_block *pmb = *pmb_p;
+	int pmb_alloc = *pmb_alloc_p, pmb_nr = *pmb_nr_p;
+
+	/*
+	 * The current line is the start of a new block.
+	 * Setup the set of potential blocks.
+	 */
+	hashmap_for_each_entry_from(hm, match, ent) {
+		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
+			if (compute_ws_delta(l, match->es, &(pmb[pmb_nr]).wsd))
+				pmb[pmb_nr++].match = match;
+		} else {
+			pmb[pmb_nr].wsd = 0;
+			pmb[pmb_nr++].match = match;
+		}
+	}
+
+	*pmb_p = pmb;
+	*pmb_alloc_p = pmb_alloc;
+	*pmb_nr_p = pmb_nr;
+}
+
 /*
  * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
  *
@@ -1198,23 +1230,8 @@ static void mark_color_as_moved(struct diff_options *o,
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
 		if (pmb_nr == 0) {
-			/*
-			 * The current line is the start of a new block.
-			 * Setup the set of potential blocks.
-			 */
-			hashmap_for_each_entry_from(hm, match, ent) {
-				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
-				if (o->color_moved_ws_handling &
-				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-					if (compute_ws_delta(l, match->es,
-							     &pmb[pmb_nr].wsd))
-						pmb[pmb_nr++].match = match;
-				} else {
-					pmb[pmb_nr].wsd = 0;
-					pmb[pmb_nr++].match = match;
-				}
-			}
-
+			fill_potential_moved_blocks(
+				o, hm, match, l, &pmb, &pmb_alloc, &pmb_nr);
 			if (adjust_last_block(o, n, block_length) &&
 			    pmb_nr && last_symbol != l->s)
 				flipped_block = (flipped_block + 1) % 2;

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 09af94e018c..1e1b5127d15 100644
--- a/diff.c
+++ b/diff.c
@@ -1205,7 +1205,15 @@ static void mark_color_as_moved(struct diff_options *o,
 		if (!match) {
 			int i;
 
-			adjust_last_block(o, n, block_length);
+			if (!adjust_last_block(o, n, block_length) &&
+			    block_length > 1) {
+				/*
+				 * Rewind in case there is another match
+				 * starting at the second line of the block
+				 */
+				match = NULL;
+				n -= block_length;
+			}
 			for(i = 0; i < pmb_nr; i++)
 				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
@@ -1230,10 +1238,20 @@ static void mark_color_as_moved(struct diff_options *o,
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
 		if (pmb_nr == 0) {
-			fill_potential_moved_blocks(
-				o, hm, match, l, &pmb, &pmb_alloc, &pmb_nr);
-			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol != l->s)
+			int contiguous = adjust_last_block(o, n, block_length);
+
+			if (!contiguous && block_length > 1)
+				/*
+				 * Rewind in case there is another match
+				 * starting at the second line of the block
+				 */
+				n -= block_length;
+			else
+				fill_potential_moved_blocks(o, hm, match, l,
+							    &pmb, &pmb_alloc,
+							    &pmb_nr);
+
+			if (contiguous && pmb_nr && last_symbol != l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 2c13b62d3c6..308dc136596 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1833,6 +1833,52 @@ test_expect_success '--color-moved treats adjacent blocks as separate for MIN_AL
 	test_cmp expected actual
 '
 
+test_expect_success '--color-moved rewinds for MIN_ALNUM_COUNT' '
+	git reset --hard &&
+	test_write_lines >file \
+		A B C one two three four five six seven D E F G H I J &&
+	git add file &&
+	test_write_lines >file \
+		one two A B C D E F G H I J two three four five six seven &&
+	git diff --color-moved=zebra -- file &&
+
+	git diff --color-moved=zebra --color -- file >actual.raw &&
+	grep -v "index" actual.raw | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/file b/file<RESET>
+	<BOLD>--- a/file<RESET>
+	<BOLD>+++ b/file<RESET>
+	<CYAN>@@ -1,13 +1,8 @@<RESET>
+	<GREEN>+<RESET><GREEN>one<RESET>
+	<GREEN>+<RESET><GREEN>two<RESET>
+	 A<RESET>
+	 B<RESET>
+	 C<RESET>
+	<RED>-one<RESET>
+	<BOLD;MAGENTA>-two<RESET>
+	<BOLD;MAGENTA>-three<RESET>
+	<BOLD;MAGENTA>-four<RESET>
+	<BOLD;MAGENTA>-five<RESET>
+	<BOLD;MAGENTA>-six<RESET>
+	<BOLD;MAGENTA>-seven<RESET>
+	 D<RESET>
+	 E<RESET>
+	 F<RESET>
+	<CYAN>@@ -15,3 +10,9 @@<RESET> <RESET>G<RESET>
+	 H<RESET>
+	 I<RESET>
+	 J<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>two<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>three<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>four<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>five<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>six<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>seven<RESET>
+	EOF
+
+	test_cmp expected actual
+'
+
 test_expect_success 'move detection with submodules' '
 	test_create_repo bananas &&
 	echo ripe >bananas/recipe &&

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 1e1b5127d15..53f0df75329 100644
--- a/diff.c
+++ b/diff.c
@@ -1176,6 +1176,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
+	enum diff_symbol last_symbol = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1183,7 +1184,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-		enum diff_symbol last_symbol = 0;
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
@@ -1251,7 +1251,7 @@ static void mark_color_as_moved(struct diff_options *o,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
-			if (contiguous && pmb_nr && last_symbol != l->s)
+			if (contiguous && pmb_nr && last_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 308dc136596..4e0fd76c6c5 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1442,6 +1442,78 @@ test_expect_success 'detect permutations inside moved code -- dimmed-zebra' '
 	test_cmp expected actual
 '
 
+test_expect_success 'zebra alternate color is only used when necessary' '
+	cat >old.txt <<-\EOF &&
+	line 1A should be marked as oldMoved newMovedAlternate
+	line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	line 2A should be marked as oldMoved newMovedAlternate
+	line 2B should be marked as oldMoved newMovedAlternate
+	line 3A should be marked as oldMovedAlternate newMoved
+	line 3B should be marked as oldMovedAlternate newMoved
+	unchanged
+	line 4A should be marked as oldMoved newMovedAlternate
+	line 4B should be marked as oldMoved newMovedAlternate
+	line 5A should be marked as oldMovedAlternate newMoved
+	line 5B should be marked as oldMovedAlternate newMoved
+	line 6A should be marked as oldMoved newMoved
+	line 6B should be marked as oldMoved newMoved
+	EOF
+	cat >new.txt <<-\EOF &&
+	  line 1A should be marked as oldMoved newMovedAlternate
+	  line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 3A should be marked as oldMovedAlternate newMoved
+	  line 3B should be marked as oldMovedAlternate newMoved
+	  line 2A should be marked as oldMoved newMovedAlternate
+	  line 2B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 6A should be marked as oldMoved newMoved
+	  line 6B should be marked as oldMoved newMoved
+	    line 4A should be marked as oldMoved newMovedAlternate
+	    line 4B should be marked as oldMoved newMovedAlternate
+	  line 5A should be marked as oldMovedAlternate newMoved
+	  line 5B should be marked as oldMovedAlternate newMoved
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		 --color-moved-ws=allow-indentation-change \
+		 old.txt new.txt >output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,14 +1,14 @@<RESET>
+	<BOLD;MAGENTA>-line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;MAGENTA>-line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;MAGENTA>-line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 53f0df75329..efba2789354 100644
--- a/diff.c
+++ b/diff.c
@@ -1176,7 +1176,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
-	enum diff_symbol last_symbol = 0;
+	enum diff_symbol moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1202,7 +1202,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			flipped_block = 0;
 		}
 
-		if (!match) {
+		if (pmb_nr && (!match || l->s != moved_symbol)) {
 			int i;
 
 			if (!adjust_last_block(o, n, block_length) &&
@@ -1219,12 +1219,13 @@ static void mark_color_as_moved(struct diff_options *o,
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
-			last_symbol = l->s;
+		}
+		if (!match) {
+			moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 			continue;
 		}
 
 		if (o->color_moved == COLOR_MOVED_PLAIN) {
-			last_symbol = l->s;
 			l->flags |= DIFF_SYMBOL_MOVED_LINE;
 			continue;
 		}
@@ -1251,11 +1252,16 @@ static void mark_color_as_moved(struct diff_options *o,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
-			if (contiguous && pmb_nr && last_symbol == l->s)
+			if (contiguous && pmb_nr && moved_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
 
+			if (pmb_nr)
+				moved_symbol = l->s;
+			else
+				moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
+
 			block_length = 0;
 		}
 
@@ -1265,7 +1271,6 @@ static void mark_color_as_moved(struct diff_options *o,
 			if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 				l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 		}
-		last_symbol = l->s;
 	}
 	adjust_last_block(o, n, block_length);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 4e0fd76c6c5..15782c879d2 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1514,6 +1514,71 @@ test_expect_success 'zebra alternate color is only used when necessary' '
 	test_cmp expected actual
 '
 
+test_expect_success 'short lines of opposite sign do not get marked as moved' '
+	cat >old.txt <<-\EOF &&
+	this line should be marked as moved
+	unchanged
+	unchanged
+	unchanged
+	unchanged
+	too short
+	this line should be marked as oldMoved newMoved
+	this line should be marked as oldMovedAlternate newMoved
+	unchanged 1
+	unchanged 2
+	unchanged 3
+	unchanged 4
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	EOF
+	cat >new.txt <<-\EOF &&
+	too short
+	unchanged
+	unchanged
+	this line should be marked as moved
+	too short
+	unchanged
+	unchanged
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 1
+	unchanged 2
+	this line should be marked as oldMovedAlternate newMoved
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 3
+	this line should be marked as oldMoved newMoved
+	unchanged 4
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		old.txt new.txt >output && cat output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expect <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,13 +1,15 @@<RESET>
+	<BOLD;MAGENTA>-this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<RED>-too short<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved<RESET>
+	<BOLD;BLUE>-this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 1<RESET>
+	 unchanged 2<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 3<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved<RESET>
+	 unchanged 4<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/diff.c b/diff.c
index efba2789354..9aff167be27 100644
--- a/diff.c
+++ b/diff.c
@@ -864,23 +864,17 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	    a_width = a->indent_width,
 	    b_off = b->indent_off,
 	    b_width = b->indent_width;
-	int delta;
 
 	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 		*out = INDENT_BLANKLINE;
 		return 1;
 	}
 
-	if (a->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - b_width;
-	else
-		delta = b_width - a_width;
-
 	if (a_len - a_off != b_len - b_off ||
 	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 		return 0;
 
-	*out = delta;
+	*out = a_width - b_width;
 
 	return 1;
 }
@@ -924,10 +918,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	if (cur->es->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - c_width;
-	else
-		delta = c_width - a_width;
+	delta = c_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its

diff --git a/diff.c b/diff.c
index 9aff167be27..78a486021ab 100644
--- a/diff.c
+++ b/diff.c
@@ -879,37 +879,21 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	return 1;
 }
 
-static int cmp_in_block_with_wsd(const struct diff_options *o,
-				 const struct moved_entry *cur,
-				 const struct moved_entry *match,
-				 struct moved_block *pmb,
-				 int n)
-{
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-	int al = cur->es->len, bl = match->es->len, cl = l->len;
+static int cmp_in_block_with_wsd(const struct moved_entry *cur,
+				 const struct emitted_diff_symbol *l,
+				 struct moved_block *pmb)
+{
+	int al = cur->es->len, bl = l->len;
 	const char *a = cur->es->line,
-		   *b = match->es->line,
-		   *c = l->line;
+		   *b = l->line;
 	int a_off = cur->es->indent_off,
 	    a_width = cur->es->indent_width,
-	    c_off = l->indent_off,
-	    c_width = l->indent_width;
+	    b_off = l->indent_off,
+	    b_width = l->indent_width;
 	int delta;
 
-	/*
-	 * We need to check if 'cur' is equal to 'match'.  As those
-	 * are from the same (+/-) side, we do not need to adjust for
-	 * indent changes. However these were found using fuzzy
-	 * matching so we do have to check if they are equal. Here we
-	 * just check the lengths. We delay calling memcmp() to check
-	 * the contents until later as if the length comparison for a
-	 * and c fails we can avoid the call all together.
-	 */
-	if (al != bl)
-		return 1;
-
 	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
@@ -918,7 +902,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	delta = c_width - a_width;
+	delta = b_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its
@@ -927,9 +911,8 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == cl - c_off &&
-		 !memcmp(a, b, al) && !
-		 memcmp(a + a_off, c + c_off, al - a_off));
+	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
+		 !memcmp(a + a_off, b + b_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -1030,36 +1013,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct moved_entry *match,
-					    struct hashmap *hm,
+					    struct emitted_diff_symbol *l,
 					    struct moved_block *pmb,
-					    int pmb_nr, int n)
+					    int pmb_nr)
 {
 	int i;
-	char *got_match = xcalloc(1, pmb_nr);
-
-	hashmap_for_each_entry_from(hm, match, ent) {
-		for (i = 0; i < pmb_nr; i++) {
-			struct moved_entry *prev = pmb[i].match;
-			struct moved_entry *cur = (prev && prev->next_line) ?
-					prev->next_line : NULL;
-			if (!cur)
-				continue;
-			if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
-				got_match[i] |= 1;
-		}
-	}
 
 	for (i = 0; i < pmb_nr; i++) {
-		if (got_match[i]) {
+		struct moved_entry *prev = pmb[i].match;
+		struct moved_entry *cur = (prev && prev->next_line) ?
+			prev->next_line : NULL;
+		if (cur && !cmp_in_block_with_wsd(cur, l, &pmb[i])) {
 			/* Advance to the next line */
-			pmb[i].match = pmb[i].match->next_line;
+			pmb[i].match = cur;
 		} else {
 			moved_block_clear(&pmb[i]);
 		}
 	}
-
-	free(got_match);
 }
 
 static int shrink_potential_moved_blocks(struct moved_block *pmb,
@@ -1223,7 +1193,7 @@ static void mark_color_as_moved(struct diff_options *o,
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
+			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
 			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 51f092e724e..626fd47aa0e 100644
--- a/diff.c
+++ b/diff.c
@@ -996,12 +996,12 @@ static void add_lines_to_move_detection(struct diff_options *o,
 static void pmb_advance_or_null(struct diff_options *o,
 				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
-				int pmb_nr)
+				int *pmb_nr)
 {
-	int i;
+	int i, j;
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
-	for (i = 0; i < pmb_nr; i++) {
+	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
@@ -1015,38 +1015,12 @@ static void pmb_advance_or_null(struct diff_options *o,
 			match = cur &&
 				xdiff_compare_lines(cur->es->line, cur->es->len,
 						    l->line, l->len, flags);
-		if (match)
-			pmb[i].match = cur;
-		else
-			moved_block_clear(&pmb[i]);
-	}
-}
-
-static int shrink_potential_moved_blocks(struct moved_block *pmb,
-					 int pmb_nr)
-{
-	int lp, rp;
-
-	/* Shrink the set of potential block to the remaining running */
-	for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
-		while (lp < pmb_nr && pmb[lp].match)
-			lp++;
-		/* lp points at the first NULL now */
-
-		while (rp > -1 && !pmb[rp].match)
-			rp--;
-		/* rp points at the last non-NULL */
-
-		if (lp < pmb_nr && rp > -1 && lp < rp) {
-			pmb[lp] = pmb[rp];
-			memset(&pmb[rp], 0, sizeof(pmb[rp]));
-			rp--;
-			lp++;
+		if (match) {
+			pmb[j] = pmb[i];
+			pmb[j++].match = cur;
 		}
 	}
-
-	/* Remember the number of running sets */
-	return rp + 1;
+	*pmb_nr = j;
 }
 
 static void fill_potential_moved_blocks(struct diff_options *o,
@@ -1181,9 +1155,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		pmb_advance_or_null(o, l, pmb, pmb_nr);
-
-		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, &pmb_nr);
 
 		if (pmb_nr == 0) {
 			int contiguous = adjust_last_block(o, n, block_length);

diff --git a/diff.c b/diff.c
index 22e0edac173..51f092e724e 100644
--- a/diff.c
+++ b/diff.c
@@ -1002,36 +1002,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0; i < pmb_nr; i++) {
+		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
-						l->line, l->len,
-						flags)) {
-			pmb[i].match = cur;
-		} else {
-			pmb[i].match = NULL;
-		}
-	}
-}
 
-static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct emitted_diff_symbol *l,
-					    struct moved_block *pmb,
-					    int pmb_nr)
-{
-	int i;
-
-	for (i = 0; i < pmb_nr; i++) {
-		struct moved_entry *prev = pmb[i].match;
-		struct moved_entry *cur = (prev && prev->next_line) ?
-			prev->next_line : NULL;
-		if (cur && !cmp_in_block_with_wsd(cur, l, &pmb[i])) {
-			/* Advance to the next line */
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			match = cur &&
+				!cmp_in_block_with_wsd(cur, l, &pmb[i]);
+		else
+			match = cur &&
+				xdiff_compare_lines(cur->es->line, cur->es->len,
+						    l->line, l->len, flags);
+		if (match)
 			pmb[i].match = cur;
-		} else {
+		else
 			moved_block_clear(&pmb[i]);
-		}
 	}
 }
 
@@ -1194,11 +1181,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
-		else
-			pmb_advance_or_null(o, l, pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 78a486021ab..22e0edac173 100644
--- a/diff.c
+++ b/diff.c
@@ -994,17 +994,20 @@ static void add_lines_to_move_detection(struct diff_options *o,
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
-				struct moved_entry *match,
-				struct hashmap *hm,
+				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
 				int pmb_nr)
 {
 	int i;
+	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
+
 	for (i = 0; i < pmb_nr; i++) {
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && !hm->cmpfn(o, &cur->ent, &match->ent, NULL)) {
+		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
+						l->line, l->len,
+						flags)) {
 			pmb[i].match = cur;
 		} else {
 			pmb[i].match = NULL;
@@ -1195,7 +1198,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
-			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
+			pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 626fd47aa0e..ffbe09937bc 100644
--- a/diff.c
+++ b/diff.c
@@ -807,11 +807,6 @@ struct moved_block {
 	int wsd; /* The whitespace delta of this block */
 };
 
-static void moved_block_clear(struct moved_block *b)
-{
-	memset(b, 0, sizeof(*b));
-}
-
 #define INDENT_BLANKLINE INT_MIN
 
 static void fill_es_indent_data(struct emitted_diff_symbol *es)
@@ -1128,8 +1123,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		}
 
 		if (pmb_nr && (!match || l->s != moved_symbol)) {
-			int i;
-
 			if (!adjust_last_block(o, n, block_length) &&
 			    block_length > 1) {
 				/*
@@ -1139,8 +1132,6 @@ static void mark_color_as_moved(struct diff_options *o,
 				match = NULL;
 				n -= block_length;
 			}
-			for(i = 0; i < pmb_nr; i++)
-				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
@@ -1193,8 +1184,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	}
 	adjust_last_block(o, n, block_length);
 
-	for(n = 0; n < pmb_nr; n++)
-		moved_block_clear(&pmb[n]);
 	free(pmb);
 }
 

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index ffbe09937bc..2085c063675 100644
--- a/diff.c
+++ b/diff.c
@@ -850,28 +850,15 @@ static void fill_es_indent_data(struct emitted_diff_symbol *es)
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
-			    const struct emitted_diff_symbol *b,
-			    int *out)
-{
-	int a_len = a->len,
-	    b_len = b->len,
-	    a_off = a->indent_off,
-	    a_width = a->indent_width,
-	    b_off = b->indent_off,
+			    const struct emitted_diff_symbol *b)
+{
+	int a_width = a->indent_width,
 	    b_width = b->indent_width;
 
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
-		*out = INDENT_BLANKLINE;
-		return 1;
-	}
-
-	if (a_len - a_off != b_len - b_off ||
-	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
-		return 0;
-
-	*out = a_width - b_width;
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+		return INDENT_BLANKLINE;
 
-	return 1;
+	return a_width - b_width;
 }
 
 static int cmp_in_block_with_wsd(const struct moved_entry *cur,
@@ -916,26 +903,17 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 			   const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
-	const struct moved_entry *a, *b;
+	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent);
-	b = container_of(entry_or_key, const struct moved_entry, ent);
+	a = container_of(eptr, const struct moved_entry, ent)->es;
+	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
 
-	if (diffopt->color_moved_ws_handling &
-	    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-		/*
-		 * As there is not specific white space config given,
-		 * we'd need to check for a new block, so ignore all
-		 * white space. The setup of the white space
-		 * configuration for the next block is done else where
-		 */
-		flags |= XDF_IGNORE_WHITESPACE;
-
-	return !xdiff_compare_lines(a->es->line, a->es->len,
-				    b->es->line, b->es->len,
-				    flags);
+	return !xdiff_compare_lines(a->line + a->indent_off,
+				    a->len - a->indent_off,
+				    b->line + b->indent_off,
+				    b->len - b->indent_off, flags);
 }
 
 static struct moved_entry *prepare_entry(struct diff_options *o,
@@ -944,7 +922,8 @@ static struct moved_entry *prepare_entry(struct diff_options *o,
 	struct moved_entry *ret = xmalloc(sizeof(*ret));
 	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
-	unsigned int hash = xdiff_hash_string(l->line, l->len, flags);
+	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
+					      l->len - l->indent_off, flags);
 
 	hashmap_entry_init(&ret->ent, hash);
 	ret->es = l;
@@ -1036,13 +1015,11 @@ static void fill_potential_moved_blocks(struct diff_options *o,
 	hashmap_for_each_entry_from(hm, match, ent) {
 		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-			if (compute_ws_delta(l, match->es, &(pmb[pmb_nr]).wsd))
-				pmb[pmb_nr++].match = match;
-		} else {
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			pmb[pmb_nr].wsd = compute_ws_delta(l, match->es);
+		else
 			pmb[pmb_nr].wsd = 0;
-			pmb[pmb_nr++].match = match;
-		}
+		pmb[pmb_nr++].match = match;
 	}
 
 	*pmb_p = pmb;
@@ -6276,10 +6253,6 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 		if (o->color_moved) {
 			struct hashmap add_lines, del_lines;
 
-			if (o->color_moved_ws_handling &
-			    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-				o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
-
 			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
 			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 15782c879d2..50d0cf486be 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -2206,10 +2206,10 @@ EMPTY=''
 test_expect_success 'compare mixed whitespace delta across moved blocks' '
 
 	git reset --hard &&
-	tr Q_ "\t " <<-EOF >text.txt &&
-	${EMPTY}
-	____too short without
-	${EMPTY}
+	tr "^|Q_" "\f\v\t " <<-EOF >text.txt &&
+	^__
+	|____too short without
+	^
 	___being grouped across blank line
 	${EMPTY}
 	context
@@ -2228,7 +2228,7 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 	git add text.txt &&
 	git commit -m "add text.txt" &&
 
-	tr Q_ "\t " <<-EOF >text.txt &&
+	tr "^|Q_" "\f\v\t " <<-EOF >text.txt &&
 	context
 	lines
 	to
@@ -2239,7 +2239,7 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 	${EMPTY}
 	QQtoo short without
 	${EMPTY}
-	Q_______being grouped across blank line
+	^Q_______being grouped across blank line
 	${EMPTY}
 	Q_QThese two lines have had their
 	indentation reduced by four spaces
@@ -2251,16 +2251,16 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 		-c core.whitespace=space-before-tab \
 		diff --color --color-moved --ws-error-highlight=all \
 		--color-moved-ws=allow-indentation-change >actual.raw &&
-	grep -v "index" actual.raw | test_decode_color >actual &&
+	grep -v "index" actual.raw | tr "\f\v" "^|" | test_decode_color >actual &&
 
 	cat <<-\EOF >expected &&
 	<BOLD>diff --git a/text.txt b/text.txt<RESET>
 	<BOLD>--- a/text.txt<RESET>
 	<BOLD>+++ b/text.txt<RESET>
 	<CYAN>@@ -1,16 +1,16 @@<RESET>
-	<BOLD;MAGENTA>-<RESET>
-	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>    too short without<RESET>
-	<BOLD;MAGENTA>-<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>^<RESET><BRED>  <RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>|    too short without<RESET>
+	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>^<RESET>
 	<BOLD;MAGENTA>-<RESET><BOLD;MAGENTA>   being grouped across blank line<RESET>
 	<BOLD;MAGENTA>-<RESET>
 	 <RESET>context<RESET>
@@ -2280,7 +2280,7 @@ test_expect_success 'compare mixed whitespace delta across moved blocks' '
 	<BOLD;YELLOW>+<RESET>
 	<BOLD;YELLOW>+<RESET>		<BOLD;YELLOW>too short without<RESET>
 	<BOLD;YELLOW>+<RESET>
-	<BOLD;YELLOW>+<RESET>	<BOLD;YELLOW>       being grouped across blank line<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>^	       being grouped across blank line<RESET>
 	<BOLD;YELLOW>+<RESET>
 	<BOLD;CYAN>+<RESET>	<BRED> <RESET>	<BOLD;CYAN>These two lines have had their<RESET>
 	<BOLD;CYAN>+<RESET><BOLD;CYAN>indentation reduced by four spaces<RESET>

diff --git a/diff.c b/diff.c
index 2085c063675..9ef88d7665a 100644
--- a/diff.c
+++ b/diff.c
@@ -1497,7 +1497,9 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len, unsigned flags)
 {
-	struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
+	struct emitted_diff_symbol e = {
+		.line = line, .len = len, .flags = flags, .s = s
+	};
 
 	if (o->emitted_symbols)
 		append_emitted_diff_symbol(o, &e);

diff --git a/diff.c b/diff.c
index 9ef88d7665a..c28c56c1283 100644
--- a/diff.c
+++ b/diff.c
@@ -18,6 +18,7 @@
 #include "submodule-config.h"
 #include "submodule.h"
 #include "hashmap.h"
+#include "mem-pool.h"
 #include "ll-merge.h"
 #include "string-list.h"
 #include "strvec.h"
@@ -772,6 +773,7 @@ struct emitted_diff_symbol {
 	int flags;
 	int indent_off;   /* Offset to first non-whitespace character */
 	int indent_width; /* The visual width of the indentation */
+	unsigned id;
 	enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -797,9 +799,9 @@ static void append_emitted_diff_symbol(struct diff_options *o,
 }
 
 struct moved_entry {
-	struct hashmap_entry ent;
 	const struct emitted_diff_symbol *es;
 	struct moved_entry *next_line;
+	struct moved_entry *next_match;
 };
 
 struct moved_block {
@@ -865,24 +867,24 @@ static int cmp_in_block_with_wsd(const struct moved_entry *cur,
 				 const struct emitted_diff_symbol *l,
 				 struct moved_block *pmb)
 {
-	int al = cur->es->len, bl = l->len;
-	const char *a = cur->es->line,
-		   *b = l->line;
-	int a_off = cur->es->indent_off,
-	    a_width = cur->es->indent_width,
-	    b_off = l->indent_off,
-	    b_width = l->indent_width;
+	int a_width = cur->es->indent_width, b_width = l->indent_width;
 	int delta;
 
-	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
+	/* The text of each line must match */
+	if (cur->es->id != l->id)
+		return 1;
+
+	/*
+	 * If 'l' and 'cur' are both blank then we don't need to check the
+	 * indent. We only need to check cur as we know the strings match.
+	 * */
+	if (a_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
 	 * The indent changes of the block are known and stored in pmb->wsd;
 	 * however we need to check if the indent changes of the current line
-	 * match those of the current block and that the text of 'l' and 'cur'
-	 * after the indentation match.
+	 * match those of the current block.
 	 */
 	delta = b_width - a_width;
 
@@ -893,22 +895,26 @@ static int cmp_in_block_with_wsd(const struct moved_entry *cur,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
-		 !memcmp(a + a_off, b + b_off, al - a_off));
+	return delta != pmb->wsd;
 }
 
-static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
-			   const struct hashmap_entry *eptr,
-			   const struct hashmap_entry *entry_or_key,
-			   const void *keydata)
+struct interned_diff_symbol {
+	struct hashmap_entry ent;
+	struct emitted_diff_symbol *es;
+};
+
+static int interned_diff_symbol_cmp(const void *hashmap_cmp_fn_data,
+				    const struct hashmap_entry *eptr,
+				    const struct hashmap_entry *entry_or_key,
+				    const void *keydata)
 {
 	const struct diff_options *diffopt = hashmap_cmp_fn_data;
 	const struct emitted_diff_symbol *a, *b;
 	unsigned flags = diffopt->color_moved_ws_handling
 			 & XDF_WHITESPACE_FLAGS;
 
-	a = container_of(eptr, const struct moved_entry, ent)->es;
-	b = container_of(entry_or_key, const struct moved_entry, ent)->es;
+	a = container_of(eptr, const struct interned_diff_symbol, ent)->es;
+	b = container_of(entry_or_key, const struct interned_diff_symbol, ent)->es;
 
 	return !xdiff_compare_lines(a->line + a->indent_off,
 				    a->len - a->indent_off,
@@ -916,55 +922,81 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 				    b->len - b->indent_off, flags);
 }
 
-static struct moved_entry *prepare_entry(struct diff_options *o,
-					 int line_no)
+static void prepare_entry(struct diff_options *o, struct emitted_diff_symbol *l,
+			  struct interned_diff_symbol *s)
 {
-	struct moved_entry *ret = xmalloc(sizeof(*ret));
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 	unsigned int hash = xdiff_hash_string(l->line + l->indent_off,
 					      l->len - l->indent_off, flags);
 
-	hashmap_entry_init(&ret->ent, hash);
-	ret->es = l;
-	ret->next_line = NULL;
-
-	return ret;
+	hashmap_entry_init(&s->ent, hash);
+	s->es = l;
 }
 
-static void add_lines_to_move_detection(struct diff_options *o,
-					struct hashmap *add_lines,
-					struct hashmap *del_lines)
+struct moved_entry_list {
+	struct moved_entry *add, *del;
+};
+
+static struct moved_entry_list *add_lines_to_move_detection(struct diff_options *o,
+							    struct mem_pool *entry_mem_pool)
 {
 	struct moved_entry *prev_line = NULL;
-
+	struct mem_pool interned_pool;
+	struct hashmap interned_map;
+	struct moved_entry_list *entry_list = NULL;
+	size_t entry_list_alloc = 0;
+	unsigned id = 0;
 	int n;
+
+	hashmap_init(&interned_map, interned_diff_symbol_cmp, o, 8096);
+	mem_pool_init(&interned_pool, 1024 * 1024);
+
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm;
-		struct moved_entry *key;
+		struct interned_diff_symbol key;
+		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+		struct interned_diff_symbol *s;
+		struct moved_entry *entry;
 
-		switch (o->emitted_symbols->buf[n].s) {
-		case DIFF_SYMBOL_PLUS:
-			hm = add_lines;
-			break;
-		case DIFF_SYMBOL_MINUS:
-			hm = del_lines;
-			break;
-		default:
+		if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS) {
 			prev_line = NULL;
 			continue;
 		}
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			fill_es_indent_data(&o->emitted_symbols->buf[n]);
-		key = prepare_entry(o, n);
-		if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
-			prev_line->next_line = key;
+			fill_es_indent_data(l);
 
-		hashmap_add(hm, &key->ent);
-		prev_line = key;
+		prepare_entry(o, l, &key);
+		s = hashmap_get_entry(&interned_map, &key, ent, &key.ent);
+		if (s) {
+			l->id = s->es->id;
+		} else {
+			l->id = id;
+			ALLOC_GROW_BY(entry_list, id, 1, entry_list_alloc);
+			hashmap_add(&interned_map,
+				    memcpy(mem_pool_alloc(&interned_pool,
+							  sizeof(key)),
+					   &key, sizeof(key)));
+		}
+		entry = mem_pool_alloc(entry_mem_pool, sizeof(*entry));
+		entry->es = l;
+		entry->next_line = NULL;
+		if (prev_line && prev_line->es->s == l->s)
+			prev_line->next_line = entry;
+		prev_line = entry;
+		if (l->s == DIFF_SYMBOL_PLUS) {
+			entry->next_match = entry_list[l->id].add;
+			entry_list[l->id].add = entry;
+		} else {
+			entry->next_match = entry_list[l->id].del;
+			entry_list[l->id].del = entry;
+		}
 	}
+
+	hashmap_clear(&interned_map);
+	mem_pool_discard(&interned_pool, 0);
+
+	return entry_list;
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
@@ -973,7 +1005,6 @@ static void pmb_advance_or_null(struct diff_options *o,
 				int *pmb_nr)
 {
 	int i, j;
-	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0, j = 0; i < *pmb_nr; i++) {
 		int match;
@@ -986,9 +1017,8 @@ static void pmb_advance_or_null(struct diff_options *o,
 			match = cur &&
 				!cmp_in_block_with_wsd(cur, l, &pmb[i]);
 		else
-			match = cur &&
-				xdiff_compare_lines(cur->es->line, cur->es->len,
-						    l->line, l->len, flags);
+			match = cur && cur->es->id == l->id;
+
 		if (match) {
 			pmb[j] = pmb[i];
 			pmb[j++].match = cur;
@@ -998,7 +1028,6 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void fill_potential_moved_blocks(struct diff_options *o,
-					struct hashmap *hm,
 					struct moved_entry *match,
 					struct emitted_diff_symbol *l,
 					struct moved_block **pmb_p,
@@ -1012,7 +1041,7 @@ static void fill_potential_moved_blocks(struct diff_options *o,
 	 * The current line is the start of a new block.
 	 * Setup the set of potential blocks.
 	 */
-	hashmap_for_each_entry_from(hm, match, ent) {
+	for (; match; match = match->next_match) {
 		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -1067,8 +1096,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
 static void mark_color_as_moved(struct diff_options *o,
-				struct hashmap *add_lines,
-				struct hashmap *del_lines)
+				struct moved_entry_list *entry_list)
 {
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
@@ -1077,23 +1105,15 @@ static void mark_color_as_moved(struct diff_options *o,
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
-		struct hashmap *hm = NULL;
-		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
-			hm = del_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].del;
 			break;
 		case DIFF_SYMBOL_MINUS:
-			hm = add_lines;
-			key = prepare_entry(o, n);
-			match = hashmap_get_entry(hm, key, ent, NULL);
-			free(key);
+			match = entry_list[l->id].add;
 			break;
 		default:
 			flipped_block = 0;
@@ -1135,7 +1155,7 @@ static void mark_color_as_moved(struct diff_options *o,
 				 */
 				n -= block_length;
 			else
-				fill_potential_moved_blocks(o, hm, match, l,
+				fill_potential_moved_blocks(o, match, l,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
@@ -6253,20 +6273,18 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 
 	if (o->emitted_symbols) {
 		if (o->color_moved) {
-			struct hashmap add_lines, del_lines;
-
-			hashmap_init(&del_lines, moved_entry_cmp, o, 0);
-			hashmap_init(&add_lines, moved_entry_cmp, o, 0);
+			struct mem_pool entry_pool;
+			struct moved_entry_list *entry_list;
 
-			add_lines_to_move_detection(o, &add_lines, &del_lines);
-			mark_color_as_moved(o, &add_lines, &del_lines);
+			mem_pool_init(&entry_pool, 1024 * 1024);
+			entry_list = add_lines_to_move_detection(o,
+								 &entry_pool);
+			mark_color_as_moved(o, entry_list);
 			if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
 				dim_moved_lines(o);
 
-			hashmap_clear_and_free(&add_lines, struct moved_entry,
-						ent);
-			hashmap_clear_and_free(&del_lines, struct moved_entry,
-						ent);
+			mem_pool_discard(&entry_pool, 0);
+			free(entry_list);
 		}
 
 		for (i = 0; i < esm.nr; i++)

diff --git a/t/perf/p4002-diff-color-moved.sh b/t/perf/p4002-diff-color-moved.sh
new file mode 100755
index 00000000000..ab2af931c04
--- /dev/null
+++ b/t/perf/p4002-diff-color-moved.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+
+test_description='Tests diff --color-moved performance'
+. ./perf-lib.sh
+
+test_perf_default_repo
+
+# The endpoints of the diff can be customized by setting TEST_REV_A
+# and TEST_REV_B in the environment when running this test.
+
+rev="${TEST_REV_A:-v2.28.0}"
+if ! rev_a="$(git rev-parse --quiet --verify "$rev")"
+then
+	skip_all="skipping because '$rev' was not found. \
+		  Use TEST_REV_A and TEST_REV_B to set the revs to use"
+	test_done
+fi
+rev="${TEST_REV_B:-v2.29.0}"
+if ! rev_b="$(git rev-parse --quiet --verify "$rev")"
+then
+	skip_all="skipping because '$rev' was not found. \
+		  Use TEST_REV_A and TEST_REV_B to set the revs to use"
+	test_done
+fi
+
+GIT_PAGER_IN_USE=1
+test_export GIT_PAGER_IN_USE rev_a rev_b
+
+test_perf 'diff --no-color-moved --no-color-moved-ws large change' '
+	git diff --no-color-moved --no-color-moved-ws $rev_a $rev_b
+'
+
+test_perf 'diff --color-moved --no-color-moved-ws large change' '
+	git diff --color-moved=zebra --no-color-moved-ws $rev_a $rev_b
+'
+
+test_perf 'diff --color-moved-ws=allow-indentation-change large change' '
+	git diff --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		$rev_a $rev_b
+'
+
+test_perf 'log --no-color-moved --no-color-moved-ws' '
+	git log --no-color-moved --no-color-moved-ws --no-merges --patch \
+		-n1000 $rev_b
+'
+
+test_perf 'log --color-moved --no-color-moved-ws' '
+	git log --color-moved=zebra --no-color-moved-ws --no-merges --patch \
+		-n1000 $rev_b
+'
+
+test_perf 'log --color-moved-ws=allow-indentation-change' '
+	git log --color-moved=zebra --color-moved-ws=allow-indentation-change \
+		--no-merges --patch -n1000 $rev_b
+'
+
+test_done

diff --git a/diff.c b/diff.c
index 52c791574b7..bd8e4ec9757 100644
--- a/diff.c
+++ b/diff.c
@@ -1114,6 +1114,8 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
  * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
  * Think of a way to unify them.
  */
+#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
+  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 static int adjust_last_block(struct diff_options *o, int n, int block_length)
 {
 	int i, alnum_count = 0;
@@ -1130,7 +1132,7 @@ static int adjust_last_block(struct diff_options *o, int n, int block_length)
 		}
 	}
 	for (i = 1; i < block_length + 1; i++)
-		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+		o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK;
 	return 0;
 }
 
@@ -1237,8 +1239,6 @@ static void mark_color_as_moved(struct diff_options *o,
 	free(pmb);
 }
 
-#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
-  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 static void dim_moved_lines(struct diff_options *o)
 {
 	int n;

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 1e1b5127d15..53f0df75329 100644
--- a/diff.c
+++ b/diff.c
@@ -1176,6 +1176,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
+	enum diff_symbol last_symbol = 0;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1183,7 +1184,6 @@ static void mark_color_as_moved(struct diff_options *o,
 		struct moved_entry *key;
 		struct moved_entry *match = NULL;
 		struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-		enum diff_symbol last_symbol = 0;
 
 		switch (l->s) {
 		case DIFF_SYMBOL_PLUS:
@@ -1251,7 +1251,7 @@ static void mark_color_as_moved(struct diff_options *o,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
-			if (contiguous && pmb_nr && last_symbol != l->s)
+			if (contiguous && pmb_nr && last_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 308dc136596..4e0fd76c6c5 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1442,6 +1442,78 @@ test_expect_success 'detect permutations inside moved code -- dimmed-zebra' '
 	test_cmp expected actual
 '
 
+test_expect_success 'zebra alternate color is only used when necessary' '
+	cat >old.txt <<-\EOF &&
+	line 1A should be marked as oldMoved newMovedAlternate
+	line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	line 2A should be marked as oldMoved newMovedAlternate
+	line 2B should be marked as oldMoved newMovedAlternate
+	line 3A should be marked as oldMovedAlternate newMoved
+	line 3B should be marked as oldMovedAlternate newMoved
+	unchanged
+	line 4A should be marked as oldMoved newMovedAlternate
+	line 4B should be marked as oldMoved newMovedAlternate
+	line 5A should be marked as oldMovedAlternate newMoved
+	line 5B should be marked as oldMovedAlternate newMoved
+	line 6A should be marked as oldMoved newMoved
+	line 6B should be marked as oldMoved newMoved
+	EOF
+	cat >new.txt <<-\EOF &&
+	  line 1A should be marked as oldMoved newMovedAlternate
+	  line 1B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 3A should be marked as oldMovedAlternate newMoved
+	  line 3B should be marked as oldMovedAlternate newMoved
+	  line 2A should be marked as oldMoved newMovedAlternate
+	  line 2B should be marked as oldMoved newMovedAlternate
+	unchanged
+	  line 6A should be marked as oldMoved newMoved
+	  line 6B should be marked as oldMoved newMoved
+	    line 4A should be marked as oldMoved newMovedAlternate
+	    line 4B should be marked as oldMoved newMovedAlternate
+	  line 5A should be marked as oldMovedAlternate newMoved
+	  line 5B should be marked as oldMovedAlternate newMoved
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		 --color-moved-ws=allow-indentation-change \
+		 old.txt new.txt >output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,14 +1,14 @@<RESET>
+	<BOLD;MAGENTA>-line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 1B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 3B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>  line 2B should be marked as oldMoved newMovedAlternate<RESET>
+	 unchanged<RESET>
+	<BOLD;MAGENTA>-line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;MAGENTA>-line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;BLUE>-line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;BLUE>-line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;MAGENTA>-line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;MAGENTA>-line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6A should be marked as oldMoved newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 6B should be marked as oldMoved newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4A should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>    line 4B should be marked as oldMoved newMovedAlternate<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5A should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>  line 5B should be marked as oldMovedAlternate newMoved<RESET>
+	EOF
+	test_cmp expected actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/diff.c b/diff.c
index bd8e4ec9757..09af94e018c 100644
--- a/diff.c
+++ b/diff.c
@@ -1098,6 +1098,38 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
 	return rp + 1;
 }
 
+static void fill_potential_moved_blocks(struct diff_options *o,
+					struct hashmap *hm,
+					struct moved_entry *match,
+					struct emitted_diff_symbol *l,
+					struct moved_block **pmb_p,
+					int *pmb_alloc_p, int *pmb_nr_p)
+
+{
+	struct moved_block *pmb = *pmb_p;
+	int pmb_alloc = *pmb_alloc_p, pmb_nr = *pmb_nr_p;
+
+	/*
+	 * The current line is the start of a new block.
+	 * Setup the set of potential blocks.
+	 */
+	hashmap_for_each_entry_from(hm, match, ent) {
+		ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
+			if (compute_ws_delta(l, match->es, &(pmb[pmb_nr]).wsd))
+				pmb[pmb_nr++].match = match;
+		} else {
+			pmb[pmb_nr].wsd = 0;
+			pmb[pmb_nr++].match = match;
+		}
+	}
+
+	*pmb_p = pmb;
+	*pmb_alloc_p = pmb_alloc;
+	*pmb_nr_p = pmb_nr;
+}
+
 /*
  * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
  *
@@ -1198,23 +1230,8 @@ static void mark_color_as_moved(struct diff_options *o,
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
 		if (pmb_nr == 0) {
-			/*
-			 * The current line is the start of a new block.
-			 * Setup the set of potential blocks.
-			 */
-			hashmap_for_each_entry_from(hm, match, ent) {
-				ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
-				if (o->color_moved_ws_handling &
-				    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
-					if (compute_ws_delta(l, match->es,
-							     &pmb[pmb_nr].wsd))
-						pmb[pmb_nr++].match = match;
-				} else {
-					pmb[pmb_nr].wsd = 0;
-					pmb[pmb_nr++].match = match;
-				}
-			}
-
+			fill_potential_moved_blocks(
+				o, hm, match, l, &pmb, &pmb_alloc, &pmb_nr);
 			if (adjust_last_block(o, n, block_length) &&
 			    pmb_nr && last_symbol != l->s)
 				flipped_block = (flipped_block + 1) % 2;

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 53f0df75329..efba2789354 100644
--- a/diff.c
+++ b/diff.c
@@ -1176,7 +1176,7 @@ static void mark_color_as_moved(struct diff_options *o,
 	struct moved_block *pmb = NULL; /* potentially moved blocks */
 	int pmb_nr = 0, pmb_alloc = 0;
 	int n, flipped_block = 0, block_length = 0;
-	enum diff_symbol last_symbol = 0;
+	enum diff_symbol moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 
 
 	for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1202,7 +1202,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			flipped_block = 0;
 		}
 
-		if (!match) {
+		if (pmb_nr && (!match || l->s != moved_symbol)) {
 			int i;
 
 			if (!adjust_last_block(o, n, block_length) &&
@@ -1219,12 +1219,13 @@ static void mark_color_as_moved(struct diff_options *o,
 			pmb_nr = 0;
 			block_length = 0;
 			flipped_block = 0;
-			last_symbol = l->s;
+		}
+		if (!match) {
+			moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
 			continue;
 		}
 
 		if (o->color_moved == COLOR_MOVED_PLAIN) {
-			last_symbol = l->s;
 			l->flags |= DIFF_SYMBOL_MOVED_LINE;
 			continue;
 		}
@@ -1251,11 +1252,16 @@ static void mark_color_as_moved(struct diff_options *o,
 							    &pmb, &pmb_alloc,
 							    &pmb_nr);
 
-			if (contiguous && pmb_nr && last_symbol == l->s)
+			if (contiguous && pmb_nr && moved_symbol == l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
 
+			if (pmb_nr)
+				moved_symbol = l->s;
+			else
+				moved_symbol = DIFF_SYMBOL_BINARY_DIFF_HEADER;
+
 			block_length = 0;
 		}
 
@@ -1265,7 +1271,6 @@ static void mark_color_as_moved(struct diff_options *o,
 			if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 				l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 		}
-		last_symbol = l->s;
 	}
 	adjust_last_block(o, n, block_length);
 
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 4e0fd76c6c5..15782c879d2 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1514,6 +1514,71 @@ test_expect_success 'zebra alternate color is only used when necessary' '
 	test_cmp expected actual
 '
 
+test_expect_success 'short lines of opposite sign do not get marked as moved' '
+	cat >old.txt <<-\EOF &&
+	this line should be marked as moved
+	unchanged
+	unchanged
+	unchanged
+	unchanged
+	too short
+	this line should be marked as oldMoved newMoved
+	this line should be marked as oldMovedAlternate newMoved
+	unchanged 1
+	unchanged 2
+	unchanged 3
+	unchanged 4
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	EOF
+	cat >new.txt <<-\EOF &&
+	too short
+	unchanged
+	unchanged
+	this line should be marked as moved
+	too short
+	unchanged
+	unchanged
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 1
+	unchanged 2
+	this line should be marked as oldMovedAlternate newMoved
+	this line should be marked as oldMoved newMoved/newMovedAlternate
+	unchanged 3
+	this line should be marked as oldMoved newMoved
+	unchanged 4
+	EOF
+	test_expect_code 1 git diff --no-index --color --color-moved=zebra \
+		old.txt new.txt >output && cat output &&
+	grep -v index output | test_decode_color >actual &&
+	cat >expect <<-\EOF &&
+	<BOLD>diff --git a/old.txt b/new.txt<RESET>
+	<BOLD>--- a/old.txt<RESET>
+	<BOLD>+++ b/new.txt<RESET>
+	<CYAN>@@ -1,13 +1,15 @@<RESET>
+	<BOLD;MAGENTA>-this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as moved<RESET>
+	<GREEN>+<RESET><GREEN>too short<RESET>
+	 unchanged<RESET>
+	 unchanged<RESET>
+	<RED>-too short<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved<RESET>
+	<BOLD;BLUE>-this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 1<RESET>
+	 unchanged 2<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMovedAlternate newMoved<RESET>
+	<BOLD;YELLOW>+<RESET><BOLD;YELLOW>this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	 unchanged 3<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>this line should be marked as oldMoved newMoved<RESET>
+	 unchanged 4<RESET>
+	<BOLD;MAGENTA>-this line should be marked as oldMoved newMoved/newMovedAlternate<RESET>
+	EOF
+	test_cmp expect actual
+'
+
 test_expect_success 'cmd option assumes configured colored-moved' '
 	test_config color.diff.oldMoved "magenta" &&
 	test_config color.diff.newMoved "cyan" &&

diff --git a/diff.c b/diff.c
index efba2789354..9aff167be27 100644
--- a/diff.c
+++ b/diff.c
@@ -864,23 +864,17 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	    a_width = a->indent_width,
 	    b_off = b->indent_off,
 	    b_width = b->indent_width;
-	int delta;
 
 	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 		*out = INDENT_BLANKLINE;
 		return 1;
 	}
 
-	if (a->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - b_width;
-	else
-		delta = b_width - a_width;
-
 	if (a_len - a_off != b_len - b_off ||
 	    memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 		return 0;
 
-	*out = delta;
+	*out = a_width - b_width;
 
 	return 1;
 }
@@ -924,10 +918,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	if (cur->es->s == DIFF_SYMBOL_PLUS)
-		delta = a_width - c_width;
-	else
-		delta = c_width - a_width;
+	delta = c_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its

diff.c, t/t4015-diff-whitespace.sh

diff --git a/diff.c b/diff.c
index 09af94e018c..1e1b5127d15 100644
--- a/diff.c
+++ b/diff.c
@@ -1205,7 +1205,15 @@ static void mark_color_as_moved(struct diff_options *o,
 		if (!match) {
 			int i;
 
-			adjust_last_block(o, n, block_length);
+			if (!adjust_last_block(o, n, block_length) &&
+			    block_length > 1) {
+				/*
+				 * Rewind in case there is another match
+				 * starting at the second line of the block
+				 */
+				match = NULL;
+				n -= block_length;
+			}
 			for(i = 0; i < pmb_nr; i++)
 				moved_block_clear(&pmb[i]);
 			pmb_nr = 0;
@@ -1230,10 +1238,20 @@ static void mark_color_as_moved(struct diff_options *o,
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 
 		if (pmb_nr == 0) {
-			fill_potential_moved_blocks(
-				o, hm, match, l, &pmb, &pmb_alloc, &pmb_nr);
-			if (adjust_last_block(o, n, block_length) &&
-			    pmb_nr && last_symbol != l->s)
+			int contiguous = adjust_last_block(o, n, block_length);
+
+			if (!contiguous && block_length > 1)
+				/*
+				 * Rewind in case there is another match
+				 * starting at the second line of the block
+				 */
+				n -= block_length;
+			else
+				fill_potential_moved_blocks(o, hm, match, l,
+							    &pmb, &pmb_alloc,
+							    &pmb_nr);
+
+			if (contiguous && pmb_nr && last_symbol != l->s)
 				flipped_block = (flipped_block + 1) % 2;
 			else
 				flipped_block = 0;
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 2c13b62d3c6..308dc136596 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -1833,6 +1833,52 @@ test_expect_success '--color-moved treats adjacent blocks as separate for MIN_AL
 	test_cmp expected actual
 '
 
+test_expect_success '--color-moved rewinds for MIN_ALNUM_COUNT' '
+	git reset --hard &&
+	test_write_lines >file \
+		A B C one two three four five six seven D E F G H I J &&
+	git add file &&
+	test_write_lines >file \
+		one two A B C D E F G H I J two three four five six seven &&
+	git diff --color-moved=zebra -- file &&
+
+	git diff --color-moved=zebra --color -- file >actual.raw &&
+	grep -v "index" actual.raw | test_decode_color >actual &&
+	cat >expected <<-\EOF &&
+	<BOLD>diff --git a/file b/file<RESET>
+	<BOLD>--- a/file<RESET>
+	<BOLD>+++ b/file<RESET>
+	<CYAN>@@ -1,13 +1,8 @@<RESET>
+	<GREEN>+<RESET><GREEN>one<RESET>
+	<GREEN>+<RESET><GREEN>two<RESET>
+	 A<RESET>
+	 B<RESET>
+	 C<RESET>
+	<RED>-one<RESET>
+	<BOLD;MAGENTA>-two<RESET>
+	<BOLD;MAGENTA>-three<RESET>
+	<BOLD;MAGENTA>-four<RESET>
+	<BOLD;MAGENTA>-five<RESET>
+	<BOLD;MAGENTA>-six<RESET>
+	<BOLD;MAGENTA>-seven<RESET>
+	 D<RESET>
+	 E<RESET>
+	 F<RESET>
+	<CYAN>@@ -15,3 +10,9 @@<RESET> <RESET>G<RESET>
+	 H<RESET>
+	 I<RESET>
+	 J<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>two<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>three<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>four<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>five<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>six<RESET>
+	<BOLD;CYAN>+<RESET><BOLD;CYAN>seven<RESET>
+	EOF
+
+	test_cmp expected actual
+'
+
 test_expect_success 'move detection with submodules' '
 	test_create_repo bananas &&
 	echo ripe >bananas/recipe &&

diff --git a/diff.c b/diff.c
index 9aff167be27..78a486021ab 100644
--- a/diff.c
+++ b/diff.c
@@ -879,37 +879,21 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
 	return 1;
 }
 
-static int cmp_in_block_with_wsd(const struct diff_options *o,
-				 const struct moved_entry *cur,
-				 const struct moved_entry *match,
-				 struct moved_block *pmb,
-				 int n)
-{
-	struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-	int al = cur->es->len, bl = match->es->len, cl = l->len;
+static int cmp_in_block_with_wsd(const struct moved_entry *cur,
+				 const struct emitted_diff_symbol *l,
+				 struct moved_block *pmb)
+{
+	int al = cur->es->len, bl = l->len;
 	const char *a = cur->es->line,
-		   *b = match->es->line,
-		   *c = l->line;
+		   *b = l->line;
 	int a_off = cur->es->indent_off,
 	    a_width = cur->es->indent_width,
-	    c_off = l->indent_off,
-	    c_width = l->indent_width;
+	    b_off = l->indent_off,
+	    b_width = l->indent_width;
 	int delta;
 
-	/*
-	 * We need to check if 'cur' is equal to 'match'.  As those
-	 * are from the same (+/-) side, we do not need to adjust for
-	 * indent changes. However these were found using fuzzy
-	 * matching so we do have to check if they are equal. Here we
-	 * just check the lengths. We delay calling memcmp() to check
-	 * the contents until later as if the length comparison for a
-	 * and c fails we can avoid the call all together.
-	 */
-	if (al != bl)
-		return 1;
-
 	/* If 'l' and 'cur' are both blank then they match. */
-	if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+	if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE)
 		return 0;
 
 	/*
@@ -918,7 +902,7 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	 * match those of the current block and that the text of 'l' and 'cur'
 	 * after the indentation match.
 	 */
-	delta = c_width - a_width;
+	delta = b_width - a_width;
 
 	/*
 	 * If the previous lines of this block were all blank then set its
@@ -927,9 +911,8 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
 	if (pmb->wsd == INDENT_BLANKLINE)
 		pmb->wsd = delta;
 
-	return !(delta == pmb->wsd && al - a_off == cl - c_off &&
-		 !memcmp(a, b, al) && !
-		 memcmp(a + a_off, c + c_off, al - a_off));
+	return !(delta == pmb->wsd && al - a_off == bl - b_off &&
+		 !memcmp(a + a_off, b + b_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -1030,36 +1013,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 }
 
 static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct moved_entry *match,
-					    struct hashmap *hm,
+					    struct emitted_diff_symbol *l,
 					    struct moved_block *pmb,
-					    int pmb_nr, int n)
+					    int pmb_nr)
 {
 	int i;
-	char *got_match = xcalloc(1, pmb_nr);
-
-	hashmap_for_each_entry_from(hm, match, ent) {
-		for (i = 0; i < pmb_nr; i++) {
-			struct moved_entry *prev = pmb[i].match;
-			struct moved_entry *cur = (prev && prev->next_line) ?
-					prev->next_line : NULL;
-			if (!cur)
-				continue;
-			if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
-				got_match[i] |= 1;
-		}
-	}
 
 	for (i = 0; i < pmb_nr; i++) {
-		if (got_match[i]) {
+		struct moved_entry *prev = pmb[i].match;
+		struct moved_entry *cur = (prev && prev->next_line) ?
+			prev->next_line : NULL;
+		if (cur && !cmp_in_block_with_wsd(cur, l, &pmb[i])) {
 			/* Advance to the next line */
-			pmb[i].match = pmb[i].match->next_line;
+			pmb[i].match = cur;
 		} else {
 			moved_block_clear(&pmb[i]);
 		}
 	}
-
-	free(got_match);
 }
 
 static int shrink_potential_moved_blocks(struct moved_block *pmb,
@@ -1223,7 +1193,7 @@ static void mark_color_as_moved(struct diff_options *o,
 
 		if (o->color_moved_ws_handling &
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
+			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
 			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 78a486021ab..22e0edac173 100644
--- a/diff.c
+++ b/diff.c
@@ -994,17 +994,20 @@ static void add_lines_to_move_detection(struct diff_options *o,
 }
 
 static void pmb_advance_or_null(struct diff_options *o,
-				struct moved_entry *match,
-				struct hashmap *hm,
+				struct emitted_diff_symbol *l,
 				struct moved_block *pmb,
 				int pmb_nr)
 {
 	int i;
+	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
+
 	for (i = 0; i < pmb_nr; i++) {
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && !hm->cmpfn(o, &cur->ent, &match->ent, NULL)) {
+		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
+						l->line, l->len,
+						flags)) {
 			pmb[i].match = cur;
 		} else {
 			pmb[i].match = NULL;
@@ -1195,7 +1198,7 @@ static void mark_color_as_moved(struct diff_options *o,
 		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
 		else
-			pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
+			pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 

diff --git a/diff.c b/diff.c
index 22e0edac173..51f092e724e 100644
--- a/diff.c
+++ b/diff.c
@@ -1002,36 +1002,23 @@ static void pmb_advance_or_null(struct diff_options *o,
 	unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 
 	for (i = 0; i < pmb_nr; i++) {
+		int match;
 		struct moved_entry *prev = pmb[i].match;
 		struct moved_entry *cur = (prev && prev->next_line) ?
 				prev->next_line : NULL;
-		if (cur && xdiff_compare_lines(cur->es->line, cur->es->len,
-						l->line, l->len,
-						flags)) {
-			pmb[i].match = cur;
-		} else {
-			pmb[i].match = NULL;
-		}
-	}
-}
 
-static void pmb_advance_or_null_multi_match(struct diff_options *o,
-					    struct emitted_diff_symbol *l,
-					    struct moved_block *pmb,
-					    int pmb_nr)
-{
-	int i;
-
-	for (i = 0; i < pmb_nr; i++) {
-		struct moved_entry *prev = pmb[i].match;
-		struct moved_entry *cur = (prev && prev->next_line) ?
-			prev->next_line : NULL;
-		if (cur && !cmp_in_block_with_wsd(cur, l, &pmb[i])) {
-			/* Advance to the next line */
+		if (o->color_moved_ws_handling &
+		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+			match = cur &&
+				!cmp_in_block_with_wsd(cur, l, &pmb[i]);
+		else
+			match = cur &&
+				xdiff_compare_lines(cur->es->line, cur->es->len,
+						    l->line, l->len, flags);
+		if (match)
 			pmb[i].match = cur;
-		} else {
+		else
 			moved_block_clear(&pmb[i]);
-		}
 	}
 }
 
@@ -1194,11 +1181,7 @@ static void mark_color_as_moved(struct diff_options *o,
 			continue;
 		}
 
-		if (o->color_moved_ws_handling &
-		    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
-			pmb_advance_or_null_multi_match(o, l, pmb, pmb_nr);
-		else
-			pmb_advance_or_null(o, l, pmb, pmb_nr);
+		pmb_advance_or_null(o, l, pmb, pmb_nr);
 
 		pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);